PZL.46 Sum (sheatfish) was a light bomber of the Polish Air Force before World War II, which, was directed to serial production in the spring of 1939. These planes were in production, but the Polish industry did not manage to produce them before the outbreak of the war.

PZL was the main Polish aerospace manufacturer of the interwar period, and a brand of their aircraft. Based in Warsaw between 1928 and 1939, PZL introduced a variety of well-regarded aircraft, most notably the PZL P.11 fighter, the PZL.23 Karaś light bomber, and the PZL.37 Łoś medium bomber.