identical to the B-25C (B-25D was made in Kansas City, Kansas; B-25C was made in Inglewood, California)
used in the United Kingdom (as the Mitchell Mk II)
B-25B - used in the Doolittle Raid. Tail gun position were removed and replaced by a manned retractable dorsal turret on the rear fuselage, and remotely operated ventral turret, each with a pair of .50 in (12.7 mm) machine guns. 120 were built. 23 were supplied to Royal Air Force as the Mitchell Mk I.
B-25C - improved version of B-25B, engines were upgraded from Wright R-2600-9 radials to R-2600-13s; de-icing and anti-icing equipment were added; the navigator received a sighting blister; and nose armament was increased to two .50 in (12.7 mm) machine guns, one fixed and one flexible. The B-25C model was the first mass-produced B-25 version; it was also used in RAF as Mitchell Mk II, in Canada, China, the Netherlands, and the Soviet Union. 1,625 were built. B-25C was made in Inglewood, California.
B-25D - Block 20, nearly identical to B-25C. B-25D was made in Kansas City, Kansas. 2,290 were built.
B-25G - modified B-25C with transparent nose replaced to create a short-nosed gunship carrying two fixed .50 in (12.7 mm) machine guns and a 75 mm M4 cannon, increased armor and a greater fuel capacity. 463 were built.
B-25H - modified B-25G, relocated the manned dorsal turret to a more forward location on the fuselage. Two additional (Total 4) fixed .50 in (12.7 mm) machine guns in the nose and four .50 in (12.7 mm) machine guns in fuselage-mounted pods (B-25H-5 onward), . The T13E1 light weight cannon replaced the heavy M4 cannon 75 mm (2.95 in). Navigator in the right seat. 1000 were built
B-25J-NC - a cross between B-25D and B-25H. It had a transparent nose and many were modified to have a strafer nose (J2). Most of its 14~18 machine guns were forward-facing for strafing missions, including the two guns of the forward-located dorsal turret. The RAF received . 4,318 were built. 316 were served in RAF as Mitchell Mk III
PBJ-1C - B-25C for U.S. Navy / U.S. Marine Corps, it was often fitted with airborne search radar and used in antisubmarine role.
PBJ-1D - B-25D for U.S. Navy / U.S. Marine Corps, it differed in having a single .50 in (12.7 mm) machine gun in the tail turret and waist gun positions similar to the B-25H. Often it was fitted with airborne search radar and used in antisubmarine role.
PBJ-1H - B-25H for U.S. Navy / U.S. Marine Corps.
PBJ-1J - B-25J for U.S. Navy / U.S. Marine Corps. USMC often fitted with 5-inch underwing rockets and search radar for antishipping/antisubmarine role.