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| | E6 |  |  |  |  | Shell Annual Report and Form 20-F 2012 |  | reports.shell.com
| |    |  |  |  |  | Exhibits                              



|            
|------------
|EXHIBIT 12.1

I, Peter Voser, certify that:

1. I have
reviewed the Annual Report on Form 20-F of Royal Dutch Shell plc (the Company);

2. Based on my knowledge, the report does not contain any untrue statement of a
material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by the report;

3. Based on my knowledge, the financial statements, and other financial information included in the report, fairly present in all material respects the financial
condition, results of operations and cash flows of the Company as of, and for, the periods presented in the report;

4. The Companys other certifying officer
and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and
15d-15(f)) for the Company and have:



|§ |  | designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the Company, including its
consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which the report is being prepared;
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|§ |  | designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of
financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;
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|§ |  | evaluated the effectiveness of the Companys disclosure controls and procedures and presented in the report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the
period covered by the report based on such evaluation; and
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|§ |  | disclosed in the report any change in the Companys internal control over financial reporting that occurred during the period covered by the annual report that has materially affected, or is reasonably likely to
materially affect, the Companys internal control over financial reporting;
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5. The Companys other certifying officer and I have disclosed,
based on our most recent evaluation of internal control over financial reporting, to the Companys auditors and the audit committee of the Companys Board of Directors (or persons performing the equivalent functions):



|§ |  | all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the Companys ability to record, process,
summarise and report financial information; and
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|§ |  | any fraud, whether or not material, that involves management or other employees who have a significant role in the Companys internal control over financial reporting.
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|                       
|-----------------------
|/s/    Peter Voser     
|Peter Voser            
|Chief Executive Officer
|March 13, 2013