Solid solution composites of (Ti,V)2AlC/Al2O3 were successfully synthesized using the in situ hot-pressing process by the incorporation of the thermit reaction of Al with V2O5 in Ti, Al, and carbon black system. The phase evolution during the formation of the composites was examined from 500°C to 1350°C, and a possible reaction mechanism was proposed to explain the formation of (Ti,V)2AlC/Al2O3 solid solution composites. The composite with 10 wt% Al2O3 possesses the best mechanical properties and the hardness, flexural strength, and fracture toughness of the composites are enhanced by 53.2%, 140%, and 180%, respectively. The strengthening and toughening mechanisms were also discussed.