Ghiyath ad-Din Mehmed Tapar (probably died in 1118) was a Seljuk leader who revolted against Sultan Ahmed Sanjar in 1104. He (probably) allied himself with Radwan of Aleppo in a battle against Kilij Arslan I, the sultan of Rüm, near Mosul in 1107, where Kilij Arslan was defeated and later killed. Mehmed was succeeded by Mahmud II.