Janet Yellen has been confirmed as the first ever female US treasury secretary in a Senate vote.
Ms Yellen, who headed the US central bank from 2014 to 2018, earlier won bipartisan support from members of the Senate Finance Committee.
She will be responsible for guiding the Biden administration's economic response to the pandemic.
The US is struggling to rebound economically from the hit caused by the coronavirus pandemic.
At her confirmation hearing on 19 January, Ms Yellen urged Congress to approve trillions more in pandemic relief and economic stimulus, saying that lawmakers should "act big" without worrying about national debt.
In response, Republican senators warned the former Federal Reserve head this was not the time for "a laundry list" of liberal reforms.
Ms Yellen disagreed, highlighting the fact that many families whose incomes have fallen were not reached by jobless programmes. She argued that plans to raise taxes must be seen in the context of financing bigger investments necessary to make the US economy competitive.
"The focus now is not on tax increases. It is on programmes to help us get through the pandemic," she stressed.
Who is Janet Yellen?
Janet Yellen was previously chair of the US Federal Reserve. She was known for focusing more attention on the impact of the central bank's policies on workers and the costs of America's rising inequality.
Before then-President Barack Obama named her to lead the Fed in 2014, she had served as one of its board members for a decade, including four years as vice-chair.
Donald Trump bucked Washington tradition when he opted not to appoint Ms Yellen to a second four-year term at the Fed.
However, her climb to the top of the economics profession had made her a feminist icon in the economics world.
When she left the Fed in 2018, many paid tribute to her leadership by imitating her signature look of a blazer with a popped collar.
Ms Yellen is seen as someone able to satisfy both progressive and centrist members of Mr Biden's Democratic party. Her nomination to lead the Fed in 2014 won support from some Republicans.
Her focus on employment, rather than inflation, gave her a reputation of favouring low interest rates, which spur economic activity by making it less expensive to borrow money.
But under her leadership, the Fed raised interest rates for the first time since 2008 - albeit less aggressively than some more conservative commentators supported.
Her stewardship of that process has won praise on Wall Street, even as it remains hotly debated.