Sinclair has failed to force his way into the Watford side since joining from Liverpool back in 2016, scoring just one goal in 12 games.
With Watford having strengthened themselves this summer, a loan move always looked likely and it is Sunderland who have won the race for his signature.
Sinclair becomes Sunderland's eighth signing of the summer, with manager Jack Ross of the oinion that he will bring some much-needed attacking thrust to his side.
"We need more players in the forward areas and Jerome is somebody who fits into that bracket," he told the club's official website.
"He can play in multiple positions across the front line. I'm pleased to get him in and he's at a stage in his career where he needs to play games.
"He's hungry to prove himself and he's got a big opportunity here to do that."
July 25, 2018