"In My Lonely Room" is a 1964 single by Motown girl group Martha and the Vandellas. In this song, which registered at #6 R&B (Cashbox) and #44 Pop, the narrator solemnly discusses how her lover's flirting with other girls leave her so depressed that all she can do was sit by "(her) lonely room and cry". The song was produced under a more solemn though still uptempo gospel-influenced number that had been on a number of the group's hits starting with "(Love Is Like a) Heat Wave". It was their fifth hit with Holland–Dozier–Holland.
The Supremes recorded a version of the song to the same instrumental track as The Vandellas with additional instrumentation in 1966. It was produced by Holland-Dozier and intended to be included on their album The Supremes A' Go-Go, but remained unreleased until 1998.