The Myasishchev M-4 Molot (Russian: Hammer, NATO reporting name Bison) is a four-engined strategic bomber, designed by Vladimir Myasishchev and developed by the Soviet Union in the 1950s to provide a bomber capable of attacking targets in North America. The Myasishchev design bureau was formed to build such a bomber.

First flying soon after the first flight of the Boeing B-52, the M-4 initially impressed Soviet officials, however, it soon became clear that the bomber had an insufficient range to attack the United States, and only several of the original production M-4s were actually put into service.

The M-4 was first displayed to the public in Red Square, on May Day, 1954.

To remedy this problem, the Myasishchev design bureau introduced the 3M, the Bison-B, which was considerably more powerful than the previous version. This new model first flew in 1955. Among other things, two of the five original gun barbettes were removed to lighten the aircraft.

This time, it was not the Air Force that wanted the 3M, but rather the Soviet Navy. Though it could still not bomb Washington DC, the 3M had a sufficient range to fulfill the need for a long-range maritime reconnaissance aircraft. In 1959, the 3M broke numerous world records, however, it was thought by the West (and would continue to be thought so until 1961) that the 3M was the original M-4, meaning that the capability of the M-4 was vastly overestimated by Western intelligence agencies.

In the early 1960s, the Bison-C, with a specialised search radar, was introduced. By this time, many of the original M-4s had been converted to M-4-2 fuel tankers for aerial refueling. Later, 3Ms were converted to 3MS-2 and 3MN-2 tankers as well.

Neither the M-4 nor the 3M ever saw combat, and none were ever converted for low altitude attack, as many American B-52s were, nor were any ever exported to the Soviet Union's allies.

Production of the Bison aircraft stopped in 1963, by which time 93 of them had been built. The last aircraft, an M-4-2 fuel tanker, was withdrawn from service in 1994.

See also: List of military aircraft of the Soviet Union and the CIS