"Port of Lonely Hearts" is a song written and originally recorded by Johnny Cash.
The song was recorded by Cash at Sun Records in 1955. Sun released it as a single (Sun 347, with "Mean-Eyed Cat" on the opposite side) in October 1960 when Cash had already left the label for Columbia.
According to C. Eric Banister's Johnny Cash FAQ: All That's Left to Know About the Man in Black,