New kid on the block

Meaning

A new arrival in an area or in a group of young friends.

Origin

Unsurprisingly, this phrase is of US origin. It is first seen there in the 1940s. The earliest citation I can find is in this 'Skippy' cartoon, by Percy Crosby, from The Lowell Sun And Citizen-Leader, December 1941.

See other phrases that were coined in the USA.