Onslow is a masculine given name and nickname which may refer to:
Onslow Humphreys (c. 1893– ?), Australian rugby union player Onslow Stearns (1810–1878), American railroad builder and politician Onslow Stevens (1902–1977), American actor Onslow Whiting (1872–1937), English sculptor Onslow (Keeping Up Appearances), British TV character