The Thomas-Morse MB-2 was an open-cockpit biplane fighter manufactured by Thomas-Morse Aircraft for the U.S. Army Air Service in 1918.
The MB-2 was designed by B. Douglas Thomas at the same time he was building the MB-1. Powered by a Liberty 12 engine, the first of two two-seat biplanes flew in November 1918. The Army was unimpressed by the performance and did not order any for production. Both prototypes were then scrapped, the second one incomplete.