Exhibit 12.1





CERTIFICATION OF THE PRINCIPAL
EXECUTIVE OFFICER


PURSUANT
TO RULE 13a-14(a) AND 15d-14(a), AS AMENDED







I,
Bjørn
Sjaastad, certify that:




1. I have
reviewed this annual report on Form 20-F of Knightsbridge Tankers
Limited;




2. Based
on my knowledge, this annual 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 this annual
report;




3. Based
on my knowledge, the financial statements, and other financial information
included in this annual 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 this annual report;




4. The
company’s other certifying officer(s) 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 the Exchange Act Rules 13a-15(f) and 15d-15(f)) for the company and
have:




a)
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 this annual report is being prepared;




b)
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;




c)
evaluated the effectiveness of the company’s disclosure controls and procedures
and presented in this report our conclusions about the effectiveness of the
disclosure controls and procedures, as of the end of the period covered by this
report based on such evaluation; and




d)
disclosed in this 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; and




5. The
company's other certifying officer(s) 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):




a) all
significant deficiencies and material weaknesses in the design or operation of
internal controls over financial reporting which are reasonably likely to
adversely affect the company’s ability to record, process, summarize and report
financial information; and




b) 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.




Date:
April 23, 2008




/s/
Bjørn
Sjaastad




Bjørn
Sjaastad


Principal
Executive Officer