Thomas Stachewicz (born 5 December 1965) is a former freestyle and backstroke swimmer, who represented Australia at three Summer Olympics. Stachewicz made his Olympic debut in the 1984 Summer Olympics in Los Angeles, where he competed in the heats of the Men's 4×200-metre freestyle relay. The Australian 4×200-metre relay team recorded national records in both the preliminaries and final, finishing with a time of 7 minutes 25.63 seconds, 0.85 of a second behind third place Great Britain. Stachewicz swam the preliminary only at this meet.