He said it was a "special moment"’ to be leading his family in prayer at his new home.
“My family and I spending our first night in Bute House after today's parliamentary vote," Mr Yousaf said on Twitter.
“A special moment leading my family in prayer in Bute House as is customary after breaking fast together.”
Mr Yousaf was formally appointed First Minister after a vote by his fellow members of the Scottish Parliament on Tuesday.
Mr Yousaf clinched a narrow victory to become SNP leader on Monday, gaining 52 per cent of the votes cast by 50,490 of its members.
He is the youngest First Minister since devolution reforms created the Scottish Parliament in 1999.
“We should all take pride in the fact that today we have sent a clear message that your colour of skin, or your faith, is not a barrier to leading the country we all call home,” Mr Yousaf said in his victory speech.
Promising to be a leader “for all of Scotland”, he pledged to start a civic movement that would “ensure our drive for independence is in fifth gear”.
“We will be the generation that delivers independence for Scotland,” he said.
He will be sworn in at a ceremony on Wednesday after formal approval from King Charles III — who republican Mr Yousaf wants to dislodge in favour of an elected head of state for Scotland.
Mr Yousaf, who was born and raised in Glasgow to parents of Pakistani heritage, is the first Muslim leader of the SNP and Scotland.
For the first time, there are now men of Asian heritage running Scotland, the UK and Ireland.