Lloyd Austin confirmed as first black US defence secretary
The 93-2 vote gave President Joe Biden his second Cabinet member.
Avril Haines was confirmed on Wednesday as the first woman to serve as director of national intelligence.
Mr Biden is expected to win approval for others on his national security team in coming days, including Antony Blinken as secretary of state.
The president is looking for Mr Austin to restore stability in the Pentagon, which went through two Senate-confirmed secretaries of defence and four who held the post on an interim basis during the Trump administration.
The only senators who voted against Mr Austin were Republicans Mike Lee of Utah and Josh Hawley of Missouri.
Before heading to the Pentagon, Mr Austin wrote on Twitter that he is especially proud to be the first black secretary of defence.
“Let’s get to work,” he wrote.
Mr Austin’s confirmation was complicated by his status as a recently retired general.
He required a waiver of a legal prohibition on a military officer serving as secretary of defence within seven years of retirement.
Mr Austin retired in 2016 after serving as the first black general to head US Central Command.
He was the first black vice chief of staff of the Army in 2012 and also served as director of the Joint Staff, a behind-the-scenes job that gave him an intimate view of the Pentagon’s inner workings.
The House and the Senate approved the waiver on Thursday, clearing the way for the Senate confirmation vote.
Mr Austin, a large man with a booming voice and a tendency to shy from publicity, describes himself as the son of a postal worker and a homemaker from Thomasville, Georgia. He has promised to speak his mind to Congress and to Mr Biden.
At his confirmation hearing on Tuesday, Mr Austin said he had not sought the nomination but was ready to lead the Pentagon without clinging to his military status and with full awareness that being a political appointee and Cabinet member requires “a different perspective and unique duties from a career in uniform”.
As vice president, Mr Biden worked closely with Mr Austin in 2010-11 to wind down US military involvement in Iraq while Mr Austin was the top US commander in Baghdad.
American forces withdrew entirely, only to return in 2014 after the so-called Islamic State extremist group captured large swathes of Iraqi territory.
At Central Command, Mr Austin was a key architect of the strategy to defeat IS in Iraq and Syria.
Mr Biden said in December when he announced Mr Austin as his nominee that he considered him “the person we need at this moment,” and that he trusts him to ensure civilian control of the military.