The need for speed in US medium bombers resulted in the Martin B-26 Marauder, an aircraft ordered off the drawing board from a design by Peyton Magruder which became notorious for a series of training accidents during its first months of service which gave it the unflattering nickname of 'Widow Maker'. In the hands of an experienced pilot, however, the B-26 was safe and effective, becoming one of the best performing medium bombers of the war. B-26s first entered combat in New Guinea and the Battle of Midway but were best known later in service with the 9th Air Force over Europe as well as in the Mediterranean and Italian campaigns with additional operation by France, South Africa, and the UK. B-26s proved devastating in the tactical raids leading up to and after D-Day and, ironically considering its initial reputation, ended the war with the lowest operational loss rate of any US medium bomber. It was retired from service only until 1948 and its designation passed on by the nascent USAF to the A-26.

The first Marauder flew on 25 November 1940 in absence of a proper prototype, entering service simply as the B-26. The first major upgrade resulted in the B-26A with increased weight and more fuel while improved armor and armament resulted in the B-26B and C (similar aircraft built in different plants) which were the main production variants throught the war. Final variants with better take-off performance were the B-26F and B-26G, these had revised wing incidence angles and were little different save for equipment changes. Some B-26 versions were also used as target tugs. The RAF also received a large number of B-26s, these saw action in the Middle East and the Mediterranean and were known as the Marauder Mk. I (B-26A), Mk. IA (B-26B), Mk. II (B-26C) and Mk. III (B-26F/G).