At 37, Yousaf is the youngest leader yet of the Scottish National Party (SNP) and is vowing to reinvigorate its flagging campaign for independence.
Humza Yousaf has been sworn in as Scotland's First Minister, becoming the first Muslim leader of a government in western Europe but already facing unrest in his party.
Yousaf was sworn in as the new leader on Wednesday at Scotland's highest court, the Court of Session in Edinburgh, as his family watched on. The ceremony blended formal tradition with his Pakistani heritage
He narrowly won the leadership race on Monday after a bruising contest that followed the surprise resignation last month of Nicola Sturgeon, who had dominated Scottish politics for almost a decade.
Yousaf has previously said he wants to replace the monarchy with an elected head of state if he achieves his dream of ending Scotland's three-centuries-long political union with England.
However, the internal disagreements over the future of the pro-independence Scottish National Party and the country re-emerged after Yousaf's main rival, Kate Forbes, quit the government.
Forbes turned down an offer to become the minister for rural affairs and islands, a step down from her previous role as finance minister, according to the BBC and Scottish newspapers.
Former health secretary Alex Neil, who backed Forbes, said the proposed post was "an insult and not a real effort to unite" the party.
Yousaf had been expected to offer his leadership rival, whom he only defeated by only about 2,000 votes, a more senior role.
READ MORE: Humza Yousaf: A trailblazer and the first Muslim to lead Scotland
This morning @HumzaYousaf was sworn in as First Minister at the Court of Session.— First Minister (@ScotGovFM) March 29, 2023
Shortly afterwards he arrived at Bute House with his family, where he will continue the process of appointing his Cabinet following the appointment of Shona Robison as Deputy First Minister. pic.twitter.com/YuswHXSzpI
'Big tent' approach
During his leadership campaign, Yousaf had said he would depart from Sturgeon's "inner circle" style of leadership in favour of a "big tent" approach.
Yousaf was spending the rest of Wednesday rounding out his cabinet after he was sworn in by Colin Sutherland, the lord president of Scotland's highest court, the Court of Session.
He said on Tuesday that Shona Robison - a close friend of Sturgeon - will serve as his deputy first minister.
UK Prime Minister Rishi Sunak congratulated Yousaf in a phone call shortly after the new SNP leader was confirmed as First Minister by the Scottish Parliament on Tuesday.
Yousaf said the call had been "constructive" -- but that he had stressed to Sunak that "the democratic wishes of Scotland's people and parliament" should be respected by London.
Sunak stressed instead that the two governments should work together on day-to-day policy matters, according t o Downing Street.
READ MORE: Scotland poised to confirm first Muslim leader Humza Yousaf