Loudon Wainwright III (also known as Album I) is the debut album of Loudon Wainwright III. It was released on vinyl in 1970 on Atlantic Records. Like his sophomore effort Album II, the album is a solo acoustic effort (his later 1970s albums became progressively more rocky). Though his ironic humor is evident, this is an altogether bleaker and more acerbic effort ("Black Uncle Remus," "Four is a Magic Number," "Glad to See You've Got Religion") than most of his 1970s work.

Reflecting another career-wide obsession, the first line of the first song on his debut album concerns growing older — a theme which persists to his newest recordings, 39 years later, at time of writing.