QuickLinks -- Click here to rapidly navigate through this documentExhibit 23.1
Consent of Independent Registered Public Accounting Firm
We hereby consent to the incorporation by reference in the Registration Statements listed below of Marathon Oil Corporation of our report dated February 28, 2007, except for Note 31 as to which the date is September 6, 2007, relating to the financial statements, management's assessment of the effectiveness of internal control over financial reporting and the effectiveness of internal control over financial reporting, which appears in this Form 8-K:
On Form S-3: | | Relating to: |
File No. | | 33-57997 | | Dividend Reinvestment Plan |
| | 333-88947 | | Dividend Reinvestment and Direct Stock Purchase Plan |
| | 333-99223 | | Marathon Oil Corporation Debt Securities, Common Stock, Preferred Stock, Warrants and Stock Purchase Contracts/Units |
| | 333-99223-01 | | Marathon Financing Trust I |
| | 333-99223-02 | | Marathon Financing Trust II |
| | 333-144874 | | Marathon Oil Corporation Debt Securities, Common Stock, Preferred Stock, Warrants and Stock Purchase Contracts/Units |
On Form S-8: | | Relating to: |
File No. | | 33-56828 | | Marathon Oil Company Thrift Plan |
| | 333-29699 | | 1990 Stock Plan |
| | 333-29709 | | Marathon Oil Company Thrift Plan |
| | 333-52751 | | 1990 Stock Plan |
| | 333-86847 | | 1990 Stock Plan |
| | 333-104910 | | Marathon Oil Corporation 2003 Incentive Compensation Plan |
| | 333-143010 | | Marathon Oil Corporation 2007 Incentive Compensation Plan |
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/s/ PRICEWATERHOUSECOOPERS LLP
Houston, Texas
September 6, 2007
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Consent of Independent Registered Public Accounting Firm