April 20, 2010

United States Securities and Exchange Commission

100 F Street, NE

Washington, DC 20549

Attn: H. Roger Schwall, Assistant Director

Dear Mr. Schwall:

On behalf of Exxon Mobil Corporation, we hereby submit ExxonMobil’s responses to the comments of the Staff of the Division of Corporation Finance of the Securities and Exchange Commission set forth in your letter dated April 8, 2010 with respect to the above-referenced Registration Statement on Form S-4 (the “Registration Statement”) filed in connection with the Agreement and Plan of Merger dated as of December 13, 2009, among ExxonMobil, XTO Energy Inc. and ExxonMobil Investment Corporation.

This letter and Amendment No. 2 to the Registration Statement (“Amendment No. 2”), which includes a related proxy statement/prospectus, are being filed with the Commission electronically today. In addition to the electronic filing, we are delivering via hand delivery a hard copy of this letter, along with five courtesy copies of Amendment No. 2 marked to indicate changes from Amendment No. 1 to the Registration Statement, which was filed on March 24, 2010.

For the convenience of the Staff, each of the Staff’s comments is reproduced below and followed by the corresponding response of ExxonMobil. All references to page numbers in ExxonMobil’s responses are to the pages in the marked version of Amendment No. 2.

To the extent that any response pertains to XTO Energy or its advisers or representatives, such response, or portion thereof, is included in this letter based on information provided to ExxonMobil by XTO Energy or its advisers or representatives, as applicable.

General

Response:

ExxonMobil acknowledges the Staff’s comment and supplementally advises the Staff that it has made all necessary conforming revisions to the Registration Statement.

Response:

ExxonMobil acknowledges the Staff’s comment.

Response:

In response to the Staff’s comment, the disclosure on pages 24 through 26 of the proxy statement/prospectus has been revised.

The Merger, page 41

Response:

In response to the Staff’s comment, XTO Energy will supplementally provide to the Staff, under separate cover and on a confidential basis, (i) the presentation delivered by Jefferies to the XTO Energy board of directors on December 10, 2009 in connection with a discussion of energy market trends and outlook and (ii) the preliminary discussion materials prepared by Barclays Capital and presented at XTO Energy board meetings on November 9, 2009, November 17, 2009 and December 10, 2009. ExxonMobil supplementally advises the Staff that, other than the materials referred to above and the final Barclays Capital presentation previously provided supplementally to the Staff, no additional presentation materials were provided to the XTO Energy board of directors by either Barclays Capital or Jefferies in connection with the board of directors’ consideration of the proposed merger.

Response:

ExxonMobil respectfully advises the Staff that, although ExxonMobil received certain non-public information from XTO Energy in the course of the due diligence investigation of XTO Energy discussed in “Background of the Merger” in connection with entering into the merger agreement, such information served only to confirm, to ExxonMobil’s satisfaction for the purposes of the transaction, that there was no material information pertaining to XTO Energy that had not been disclosed to the public. Examples of the types of non-public information provided to ExxonMobil included sample individual well performance logs and cost data; the XTO Energy reserve reports prepared by XTO Energy’s third-party petroleum consultant, Miller and Lents, Ltd.; copies of agreements, board minutes and filed tax returns; salary and benefits data; and other backup or sample information. None of the information provided to ExxonMobil in the course of its due diligence investigation of XTO Energy led ExxonMobil to believe that any material information was misstated or omitted in XTO Energy’s public filings, which are incorporated by reference into the Registration Statement. ExxonMobil supplementally advises the Staff that at no time during such due diligence investigation did XTO Energy provide any financial projections, forecasts or similar forward-looking information to ExxonMobil. Accordingly, ExxonMobil respectfully submits to the Staff that the non-public information that it received in the course of its due diligence investigation of XTO Energy is not material to XTO Energy stockholders’ decision with respect to whether to vote to adopt the merger agreement. For these reasons, ExxonMobil respectfully reiterates its view that it was not provided with any material non-public information in the course of its due diligence investigation of XTO Energy.

Background of the Merger, page 41

Response:

In response to the Staff’s comment, the disclosure on pages 45 and 46 of the proxy statement/prospectus has been revised.

Response:

In response to the Staff’s comment, the disclosure on page 43 of the proxy statement/prospectus has been revised.

XTO Energy Reasons for the Merger; Recommendation of the XTO Energy Board of Directors, page 53

Response:

ExxonMobil respectfully advises the Staff that the XTO Energy board of directors considered XTO Energy’s unproved reserves and non-proved resource potential as part of the total mix of information considered in connection with the proposed merger, and that the XTO Energy board of directors did not give separate or individual consideration to XTO Energy’s unproved reserves or non-proved resource potential in the course of its consideration of the proposed merger or its determination to approve the merger agreement and recommend the adoption thereof by XTO Energy’s stockholders. Accordingly, ExxonMobil respectfully advises the Staff that XTO Energy does not believe separate or additional disclosure of the XTO Energy board of directors’ consideration of unproved reserves or non-proved resource potential in the proxy statement/prospectus would be appropriate.

ExxonMobil Reasons for the Merger, page 57

Response:

ExxonMobil respectfully advises the Staff that, although ExxonMobil believes that the merger will create significant technical and operational synergies and benefits as discussed in “ExxonMobil Reasons for the Merger,” it does not believe that the value of such synergies and benefits can be reliably estimated because they will be based on enhancements to future resource development, rather than on more easily quantifiable cost reductions, and are likely to be realized over the course of many years, rather than in the more foreseeable short term. In addition, ExxonMobil respectfully advises the Staff that any cost reductions resulting from the merger are not expected to be material and ExxonMobil did not assign a value to such savings in making its valuation assessments with respect to the transaction. Accordingly, for the foregoing reasons, ExxonMobil respectfully submits that it is not practicable to quantify the anticipated synergies and benefits from the merger or provide quantitative disclosure of the same in the proxy statement/prospectus.

Opinion of XTO Energy’s Financial Advisor, page 58

Response:

ExxonMobil respectfully advises the Staff that, as disclosed on page 72 of the proxy statement/prospectus, XTO Energy does not, as a matter of course, prepare projected financial data for extended periods. ExxonMobil supplementally advises the Staff that, because the information prepared by XTO Energy as part of its regular internal business planning process covers limited time periods, XTO Energy and Barclays Capital believed that such information would have had limited value for purposes of Barclays Capital’s analysis. Accordingly, ExxonMobil supplementally advises the Staff that, upon the advice of XTO Energy, Barclays Capital instead used the XTO Energy research projections and the projected financial data prepared by Barclays Capital in consultation with, and with the guidance of, the management of XTO Energy, as disclosed in “Opinion of XTO Energy’s Financial Advisor” and “Certain Projected Financial Data Prepared by Barclays Capital for Purposes of Rendering its Opinion,” to evaluate the future financial performance of XTO Energy.

Response:

ExxonMobil supplementally advises the Staff that, consistent with the response to comment 10 above, management of XTO Energy reviewed the projected financial data prepared by Barclays Capital after being informed by Barclays Capital of the purposes for which such projections would be used, and determined, based on this review, that the projected financial data prepared by Barclays Capital in consultation with, and with the guidance of, the management of XTO Energy was a reasonable basis upon which to evaluate the future performance of XTO Energy and that it was appropriate for Barclays Capital to use such projections in performing its financial analyses in connection with rendering its opinion.

Response:

In response to the Staff’s comment, the disclosure on page 64 of the proxy statement/prospectus has been revised.

Expand the disclosure under “Net Asset Valuation Analysis” to clarify the percentage of value attributed to XTO Energy’s non-proved resource potential in that analysis.

Response:

In response to the Staff’s comment, the disclosure on page 65 of the proxy statement/prospectus has been revised.

Response:

ExxonMobil supplementally advises the Staff that Barclays Capital did not evaluate the materiality of hedging levels, on a standalone basis, as a consideration in Barclays Capital’s net asset valuation analysis. ExxonMobil supplementally advises the Staff that hedging levels were one of numerous factors considered by Barclays Capital in conducting its net asset valuation analysis, but that Barclays Capital did not attribute any particular weight to hedging levels. Rather, ExxonMobil supplementally advises the Staff that Barclays Capital made qualitative judgments as to the significance and relevance of hedging levels relative to all other analyses and factors performed and considered by it and in the context and circumstances of the proposed merger.

Response:

Upon the advice of XTO Energy, ExxonMobil supplementally advises the Staff to refer to page 16 of the final board presentation that was delivered by Barclays Capital to the XTO Energy board of directors on December 13, 2009, a copy of which has previously been provided to the Staff under separate cover and on a confidential basis, which summarizes Barclays Capital’s analysis of ExxonMobil’s liquidity and public float based on numerous metrics. ExxonMobil supplementally advises the Staff that Barclays Capital determined, based on its analysis of the liquidity of ExxonMobil common stock, that ExxonMobil common stock is readily interchangeable with cash, and based on Barclays Capital’s judgment, the analysis it performed was sufficient to evaluate the fairness of the proposed merger to the XTO Energy stockholders from a financial point of view. Accordingly, ExxonMobil supplementally advises the Staff that Barclays Capital determined, based on its judgment, that it was not necessary to expand Barclays Capital’s evaluation of ExxonMobil beyond the evaluation reflected in such board presentation (including pages 13 through 15 thereof), whether with respect to ExxonMobil’s future financial performance or otherwise.

Comparable Transaction Analysis, page 64

Response:

ExxonMobil supplementally advises the Staff that the “third-party research firm” referenced on page 67 of the proxy statement/prospectus is a subscription-based research firm. ExxonMobil respectfully submits to the Staff that, because the estimates referenced were not commissioned or otherwise paid for in conjunction with the proposed merger and because Barclays Capital does not believe that the identity of the third-party research firm is material to an understanding of Barclays Capital’s analysis, such third-party research firm does not need to be identified in the proxy statement/prospectus. With respect to the estimates referenced, ExxonMobil respectfully advises the Staff that Barclays Capital will respond with additional information responsive to the Staff’s comment under separate cover and on a confidential basis.

Research Analyst Price Targets, page 67

Response:

In response to the Staff’s comment, the disclosure on page 69 of the proxy statement/prospectus has been revised.

Response:

ExxonMobil respectfully advises the Staff that “the implied equity value range per XTO Energy share yielded by Barclays Capital’s research analyst target price analysis” is the range of $48.00 to $60.00 per share referenced in the immediately preceding sentence on page 69 of the proxy statement/prospectus. In response to the Staff’s comment, the disclosure on page 69 of the proxy statement/prospectus has been revised.

Certain Projected Financial Data Prepared by Barclays Capital for Purposes of Rendering its Opinion, page 70

Response:

In response to the Staff’s comment, the above-referenced disclaimer has been removed and the disclosure on page 72 of the proxy statement/prospectus has been revised in light of the removal of such disclaimer.

Relationship with Jefferies, page 105

Response:

In response to the Staff’s comment with respect to the advisory services performed by Jefferies, the disclosure on pages 44, 52 and 108 of the proxy statement/prospectus has been revised to provide further detail regarding such services, including an expanded description of the presentation delivered by Jefferies to the XTO Energy board of directors on December 10, 2009 in connection with a discussion of energy market trends and outlook.

In response to the Staff’s comment with respect to whether Jefferies provided any report, opinion or appraisal within the meaning of Item 1015(b) of Regulation M-A, ExxonMobil respectfully advises the Staff that, in XTO Energy’s view, Jefferies did not provide any such report, opinion or appraisal. In particular, ExxonMobil supplementally advises the Staff that Jefferies did not provide an opinion to the XTO Energy board of directors as to the fairness, from a financial point of view, of the merger consideration to the holders of shares of XTO Energy common stock. In addition, ExxonMobil supplementally advises the Staff that the presentation delivered by Jefferies to the XTO Energy board of directors on December 10, 2009 and referred to above (and which is being supplementally provided to the Staff by XTO Energy as noted in the response to comment 4 above) consisted of a general review and discussion of energy market trends and outlook and did not contain an analysis or review of the proposed merger or any other potential strategic transaction or the fairness of the consideration to be received by XTO

Energy’s stockholders in the proposed merger. ExxonMobil respectfully advises the Staff that XTO Energy does not believe that, in the context of the proposed merger, such presentation is a report, opinion or appraisal within the meaning of Item 1015(b) of Regulation M-A.

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Please contact the undersigned at (212) 450-4539 or George R. Bason, Jr. at (212) 450-4340 should you require further information or have any questions.