In the customary ceremony at the highest court in Scotland, Mr Yousaf pledged his allegiance to the King, as well as to serve him in the role as First Minister and Keeper of the Seal of Scotland.
His family watched on from the public gallery, and he was flanked by Lord Advocate Dorothy Bain KC.
Mr Yousaf will spend the rest of Wednesday appointing his Cabinet, with his chosen ministers set to visit his official residence at Bute House throughout the day before an announcement later in the afternoon.
5. Humza Yousaf with the Great Seal of Scotland after being sworn in
Humza Yousaf with the Great Seal of Scotland after being sworn in as First Minister of Scotland Photo: PA
6. The Great Seal of Scotland on the front bench of the court
The Great Seal of Scotland on the front bench of the court as Humza Yousaf is sworn in as First Minister of Scotland at the Court of Session Photo: Jane Barlow
7. The Court of Session
His family watched on from the public gallery, and he was flanked by Lord Advocate Dorothy Bain KC. Photo: PA
8. Humza Yousaf at Bute House
Humza Yousaf at Bute House, Edinburgh, ahead of his first cabinet meeting as the newly elected First Minster of Scotland. Picture date: Wednesday March 29, 2023. Photo: Andrew Milligan