The Scottish international, 28 next month, has signed a four-year deal at Craven Cottage, with an option of a further 12 months potentially keeping him at the club until 2019.
The conclusion to the deal brings an end to a protracted saga over the future of the striker who is believed to have signed in a deal worth around £11 million.
The wantaway striker had stayed behind in England while his United team-mates are being put through their paces at their two-week training camp in northern Italy, with the Scot’s future having been massively uncertain after he tabled a transfer request last month.
Fulham saw a £5m bid turned down in June, but have maintained their interest and despite Leeds releasing a statement last week saying that the forward wasn’t for sale, it has not put off the Cottagers, with parachute money to spend following their relegation to the Championship.