The Masovian Cavalry Brigade (Polish: Mazowiecka Brygada Kawalerii) was a cavalry unit of the Polish Army in the interbellum period, which took part in the Polish September Campaign. It was created on April 1, 1937, out of former 1st Cavalry Brigade. Its headquarters were in Warsaw, with other units stationed in towns around the capital:
- 1st Józef Piłsudski Chevau-légers Regiment, garrisoned in Warsaw,
- 7th Lublin Uhlan Regiment, stationed in Mińsk Mazowiecki,
- 11th Legions Uhlan Regiment of Marshal Edward Smigly-Rydz, stationed in Ciechanów
- 4th Łęczyca Mounted Rifles Regiment, stationed in Płock,
- 1st General Józef Bem Mounted Artillery Regiment, stationed in Warsaw,
- 1st Squadron of Pioneers, stationed in Warsaw,
- 1st Squadron of Communication, stationed in Warsaw,