The Polish I Corps (Polish: I Korpus Polski; from 1942, Polish I Armored-Mechanized Corps, Polish: I Korpus Pancerno-Motorowy) was a tactical unit of the Polish Armed Forces in the West during World War II.
It was formed in the United Kingdom on 28 September 1940. It was subordinate to the Scottish Command, and the Corps HQ was located in Perthshire (Moncreiffe House near Bridge of Earn). It numbered 3498 officers and 10,884 soldiers.
Initially formed to protect a 200 kilometres (120 mi) stretch of Scottish shore between the Firth of Forth and Montrose against a possible German invasion of Britain, it became the logistical core of the Polish Army fighting alongside the Allies.
For most of its existence the core of the corps was composed of a variety of en cadre units. Once these had been formed into full tactical units, they were dispatched to the fronts of World War II separately, as part of other Allied tactical units. Among the units created out of First Corps' nominal infantry brigades were 1st Armoured Division, 1st Independent Parachute Brigade, 1st Reconnaissance Regiment and a variety of other detachments.
It was not until after the capitulation of Germany in May 1945 that the corps started to act as a single unit. Its two largest components were joined together in Northern Germany and took part in the occupation of Germany as part of the Allied forces stationed around the port of Wilhelmshaven. Prior to that date both of its main units fought separately and were grouped together mostly for logistical reasons.