Dundee United are happy for Watt to move on from Tannadice this month and the striker has been looking at his options.
Oostende were bidding to tempt Watt to Belgium, while Motherwell were keen to see the striker back plying his trade at Fir Park.
He is though heading to St Mirren, where a loan deal will see him play until the end of the season.
It is claimed St Mirren will confirm the arrival of the striker later this afternoon, with the deal done and dusted.
Watt will look to hit the ground running in Paisley and make an impact at St Mirren.
The 29-year-old former Celtic man has scored four goals in the Scottish Premiership so far this season and St Mirren will back him to add to that number in the coming months.
Watt joined Dundee United in the winter transfer window last year and signed a contract until 2025.
