The Tupolev I-4 was a Soviet sesquiplane single-seat fighter.

After the first prototype (under the development name Andrei Nikolayevich Tupolev fighter 5 | ANT-5), the I-4 was redesigned with a new engine cowling to decrease drag, with added rocket launchers on the upper wing and a larger tailfin.

The lower wing was predominantly an attachment for the wing struts; it was almost removed in the second series, the I-4Z (where the lower wings were greatly shortened), and totally removed from the I-4bis, thus transforming the aircraft from a sesquiplane into a parasol-wing monoplane.

The I-4 was used as a parasite fighter in experiments with the Tupolev TB-1 bomber.

[1] Data from [citation needed]General characteristics Performance Armament