With little discussion, the panel on a voice vote approved Deborah Kay Jones, a career diplomat who has served in Kuwait, Argentina, Syria, Iraq and Turkey.
Senator Bob Menendez, a Democrat and chairman of the committee, praised Jones and spoke of the imperative of filling the job amid increasing lawlessness in Libya.
Yesterday, a deadly car bomb exploded near a hospital in Benghazi and officials gave conflicting numbers on the death toll.
If confirmed by the full Senate, Jones would take over an ambassadorship that has been vacant for nearly eight months.
The Obama administration's response to the attacks has been the subject of a long-running and bitter dispute with congressional Republicans. They have accused the administration of trying to cover up details of the assault and its aftermath.