Exhibit 99.1

Celanese Corporation Reports First Quarter 2023 Earnings

First Quarter 2023 Financial Highlights:

Recent Highlights:

First Quarter 2023 Business Segment Overview

Acetyl Chain

Engineered Materials

Cash Flow and Tax

Outlook

Forward-Looking Statements

This release may contain "forward-looking statements," which include information concerning the Company's plans, objectives, goals, strategies, future revenues, cash flow, financial performance, synergies, capital expenditures, financing needs and other information that is not historical information. All forward-looking statements are based upon current expectations and beliefs and various assumptions. There can be no assurance that the Company will realize these expectations or that these beliefs will prove correct. There are a number of risks and uncertainties that could cause actual results to differ materially from the results expressed or implied in the forward-looking statements contained in this release. These risks and uncertainties include, among other things: changes in general economic, business, political and regulatory conditions in the countries or regions in which we operate; volatility or changes in the price and availability of raw materials and energy, particularly changes in the demand for, supply of, and market prices of ethylene, methanol, natural gas, wood pulp and fuel oil and the prices for electricity and other energy sources; the length and depth of product and industry business cycles, particularly in the automotive, electrical, mobility, textiles, medical, electronics and construction industries; the ability to pass increases in raw material prices, logistics costs and other costs on to customers or otherwise improve margins through price increases; the accuracy or inaccuracy of our beliefs or assumptions regarding anticipated benefits of the acquisition (the "M&M Acquisition") by us of the majority of the Mobility & Materials business (the "M&M Business") of DuPont de Nemours, Inc.; the possibility that we will not be able to realize all of the anticipated improvements in the M&M Business's financial performance — including optimizing pricing, currency mix and inventory — or realize all of the anticipated benefits of the M&M Acquisition, including synergies and growth opportunities, within the anticipated timeframe, or at all, whether as a result of difficulties arising from the operation or integration of the M&M Business or other unanticipated delays, costs, inefficiencies or liabilities; increased commercial, legal or regulatory complexity of entering into, or expanding our exposure to, certain end markets and geographies; risks in the global economy and equity and credit markets and their potential impact on our ability to pay down debt in the future and/or refinance at suitable rates, in a timely manner, or at all; diversion of management's attention from ongoing business operations and opportunities and other disruption caused by the M&M Acquisition and the integration processes and their impact on our existing business and relationships; risks and costs associated with increased leverage from the M&M Acquisition, including increased interest expense and potential reduction of business and strategic flexibility; the ability to maintain plant utilization rates and to implement planned capacity additions, expansions and maintenance; the ability to reduce or maintain their current levels of production costs and to improve productivity by implementing technological improvements to existing plants; increased price competition and the introduction of competing products by other companies; the ability to identify desirable potential acquisition or divestiture opportunities and to complete such transactions, including obtaining regulatory approvals, consistent with the Company's strategy; market acceptance of our products and technology; compliance and other costs and potential disruption or interruption of production or operations due to accidents, interruptions in sources of raw materials, transportation, logistics or supply chain disruptions, cybersecurity incidents, terrorism or political unrest, public health crises (including, but not limited to, the COVID-19 pandemic), or other unforeseen events or delays in construction or operation of facilities, including as a result of geopolitical conditions, the occurrence of acts of war (such as the Russia-Ukraine conflict) or terrorist incidents or as a result of weather, natural disasters, or other crises; the ability to obtain governmental approvals and to construct facilities on terms and schedules acceptable to the Company; changes in applicable tariffs, duties and trade agreements, tax rates or legislation throughout the world including, but not limited to, adjustments, changes in estimates or interpretations or the resolution of tax examinations or audits that may impact recorded or future tax impacts and potential regulatory and legislative tax developments in the United States and other jurisdictions; changes in the degree of intellectual property and other legal protection afforded to our products or technologies, or the theft of such intellectual property; potential liability for remedial actions and increased costs under existing or future environmental, health and safety regulations, including those relating to climate change or other sustainability matters; potential liability resulting from pending or future claims or litigation, including investigations or enforcement actions, or from changes in the laws, regulations or policies of governments or other governmental activities in the countries in which we operate; changes in currency exchange rates and interest rates; our level of indebtedness, which could diminish our ability to raise additional capital to fund operations or limit our ability to react to changes in the economy or the chemicals industry; tax rates and changes thereto; our ability to obtain regulatory approval for, and satisfy closing conditions to, any transactions described herein that have not closed; and various other factors discussed from time to time in the Company's filings with the Securities and Exchange Commission.

Any forward-looking statement speaks only as of the date on which it is made, and the Company undertakes no obligation to update any forward-looking statements to reflect events or circumstances after the date on which it is made or to reflect the occurrence of anticipated or unanticipated events or circumstances.

Non-GAAP Financial Measures

Presentation

This document presents the Company's two business segments, Engineered Materials and the Acetyl Chain.

Use of Non-US GAAP Financial Information

This release uses the following Non-US GAAP measures: adjusted EBIT, adjusted EBIT margin, operating EBITDA, operating EBITDA margin, adjusted earnings per share and free cash flow. These measures are not recognized in accordance with US GAAP and should not be viewed as an alternative to US GAAP measures of performance or liquidity. The most directly comparable financial measure presented in accordance with US GAAP in our consolidated financial statements for adjusted EBIT and operating EBITDA is net earnings (loss) attributable to Celanese Corporation; for adjusted EBIT margin is operating margin; for operating EBITDA margin is operating margin; for adjusted earnings per share is earnings (loss) from continuing operations attributable to Celanese Corporation per common share-diluted; and for free cash flow is net cash provided by (used in) operations.

Definitions of Non-US GAAP Financial Measures

provide reconciliations for adjusted earnings per share on a forward-looking basis (including those contained in this document) when we are unable to provide a meaningful or accurate calculation or estimation of reconciling items and the information is not available without unreasonable effort. This is due to the inherent difficulty of forecasting the timing and amount of Certain Items, such as mark-to-market pension gains and losses, that have not yet occurred, are out of our control and/or cannot be reasonably predicted. For the same reasons, we are unable to address the probable significance of the unavailable information.

Note: The income tax expense (benefit) on Certain Items ("Non-GAAP adjustments") is determined using the applicable rates in the taxing jurisdictions in which the Non-GAAP adjustments occurred and includes both current and deferred income tax expense (benefit). The income tax rate used for adjusted earnings per share approximates the midpoint in a range of forecasted tax rates for the year. This range may include certain partial or full-year forecasted tax opportunities and related costs, where applicable, and specifically excludes changes in uncertain tax positions, discrete recognition of GAAP items on a quarterly basis, other pre-tax items adjusted out of our GAAP earnings for adjusted earnings per share purposes and changes in management's assessments regarding the ability to realize deferred tax assets for GAAP. In determining the adjusted earnings per share tax rate, we reflect the impact of foreign tax credits when utilized, or expected to be utilized, absent discrete events impacting the timing of foreign tax credit utilization. We analyze this rate quarterly and adjust it if there is a material change in the range of forecasted tax rates; an updated forecast would not necessarily result in a change to our tax rate used for adjusted earnings per share. The adjusted tax rate is an estimate and may differ from the actual tax rate used for GAAP reporting in any given reporting period. Table 3a of our Non-US GAAP Financial Measures and Supplemental Information document summarizes the reconciliation of our estimated GAAP effective tax rate to the adjusted tax rate. The estimated GAAP rate excludes discrete recognition of GAAP items due to our inability to forecast such items. As part of the year-end reconciliation, we will update the reconciliation of the GAAP effective tax rate to the adjusted tax rate for actual results.

    Reconciliation of Non-US GAAP Financial Measures

Results Unaudited

The results in this document, together with the adjustments made to present the results on a comparable basis, have not been audited and are based on internal financial data furnished to management. Quarterly results should not be taken as an indication of the results of operations to be reported for any subsequent period or for the full fiscal year.

Supplemental Information

Additional information about our prior period performance is included in our Quarterly Reports on Form 10-Q and in our Non-US GAAP Financial Measures and Supplemental Information document.

Consolidated Statements of Operations - Unaudited

Consolidated Balance Sheets - Unaudited

Non-US GAAP Financial Measures and Supplemental Information

May 9, 2023

In this document, the terms the "Company," "we" and "our" refer to Celanese Corporation and its subsidiaries on a consolidated basis.

Purpose

The purpose of this document is to provide information of interest to investors, analysts and other parties including supplemental financial information and reconciliations and other information concerning our use of non-US GAAP financial measures. This document is updated quarterly.

Presentation

This document presents the Company's two business segments, Engineered Materials and the Acetyl Chain.

Use of Non-US GAAP Financial Measures

From time to time, management may publicly disclose certain numerical "non-GAAP financial measures" in the course of our earnings releases, financial presentations, earnings conference calls, investor and analyst meetings and otherwise. For these purposes, the Securities and Exchange Commission ("SEC") defines a "non-GAAP financial measure" as a numerical measure of historical or future financial performance, financial position or cash flows that excludes amounts, or is subject to adjustments that effectively exclude amounts, included in the most directly comparable measure calculated and presented in accordance with US GAAP, and vice versa for measures that include amounts, or are subject to adjustments that effectively include amounts, that are excluded from the most directly comparable US GAAP measure so calculated and presented. For these purposes, "GAAP" refers to generally accepted accounting principles in the United States.

Non-GAAP financial measures disclosed by management are provided as additional information to investors, analysts and other parties because the Company believes them to be important supplemental measures for assessing our financial and operating results and as a means to evaluate our financial condition and period-to-period comparisons. These non-GAAP financial measures should be viewed as supplemental to, and should not be considered in isolation or as alternatives to, net earnings (loss), operating profit (loss), operating margin, cash flow from operating activities (together with cash flow from investing and financing activities), earnings per share or any other US GAAP financial measure. These non-GAAP financial measures should be considered within the context of our complete audited and unaudited financial results for the given period, which are available on the Financial Information/Financial Document Library page of our website, investors.celanese.com. The definition and method of calculation of the non-GAAP financial measures used herein may be different from other companies' methods for calculating measures with the same or similar titles. Investors, analysts and other parties should understand how another company calculates such non-GAAP financial measures before comparing the other company's non-GAAP financial measures to any of our own. These non-GAAP financial measures may not be indicative of the historical operating results of the Company nor are they intended to be predictive or projections of future results.

Pursuant to the requirements of SEC Regulation G, whenever we refer to a non-GAAP financial measure, we will also present in this document, in the presentation itself or on a Form 8-K in connection with the presentation on the Financial Information/Financial Document Library page of our website, investors.celanese.com, to the extent practicable, the most directly comparable financial measure calculated and presented in accordance with GAAP, along with a reconciliation of the differences between the non-GAAP financial measure we reference and such comparable GAAP financial measure.

This document includes definitions and reconciliations of non-GAAP financial measures used from time to time by the Company.

Specific Measures Used

This document provides information about the following non-GAAP measures: adjusted EBIT, adjusted EBIT margin, operating EBITDA, operating EBITDA margin, operating profit (loss) attributable to Celanese Corporation, adjusted earnings per share, net debt, free cash flow and return on invested capital (adjusted). The most directly comparable financial measure presented in accordance with US GAAP in our consolidated financial statements for adjusted EBIT and operating EBITDA is net earnings (loss) attributable to Celanese Corporation; for adjusted EBIT margin and operating EBITDA margin is operating margin; for operating profit (loss) attributable to Celanese Corporation is operating profit (loss); for adjusted earnings per share is earnings (loss) from continuing operations attributable to Celanese Corporation per common share-diluted; for net debt

is total debt; for free cash flow is net cash provided by (used in) operations; and for return on invested capital (adjusted) is net earnings (loss) attributable to Celanese Corporation divided by the sum of the average of beginning and end of the year short- and long-term debt and Celanese Corporation stockholders' equity.

Definitions

Supplemental Information

Supplemental Information we believe to be of interest to investors, analysts and other parties includes the following:

Results Unaudited

The results in this document, together with the adjustments made to present the results on a comparable basis, have not been audited and are based on internal financial data furnished to management. Quarterly results should not be taken as an indication of the results of operations to be reported for any subsequent period or for the full fiscal year.

Table 1

Celanese Adjusted EBIT and Operating EBITDA - Reconciliation of Non-GAAP Measures - Unaudited

Table 1a

M&M Adjusted EBIT and Operating EBITDA - Reconciliation of Non-GAAP Measures - Unaudited