The Senate also confirmed Robert Stephen Beecroft as the new envoy to Iraq. US President Barack Obama nominated both diplomats.
The appointment new ambassador to Pakistan will aim to turn a page in diplomatic relations with Islamabad.
Olson, 30, is a veteran of the US State Department and has served as an envoy to the UAE between 2008 and 2011, AFP reported.
The outgoing American ambassador to Pakistan, Cameron Munter, resigned in May after a turbulent tenure in which a covert US forces raid killed Osama bin Laden near a major military academy, humiliating the country’s powerful army.
Beecroft has served at the US embassy in Baghdad since July 2011, first as the deputy chief of mission and from June this year as the charge d’affaires.