The powerful striker, who stands at 6ft 4in, joins City on loan until the end of the season.
Kargbo moved to QPR at the age of just 12 from Mass Elite Academy and was a regular for Rangers’ Under-23s last season.
In pre-season, he joined Vanarama National League side Southend United on loan and made five appearances whilst at Roots Hall.
Welcome to Oxford City, Hamza!
You can see Hamza in action at the Velocity Stadium as we take on Dartford on 2nd April (3pm KO) - click HERE to get your tickets.