"Mr. Spaceman" is a song by the American rock band the Byrds and was the third track on their 1966 album, Fifth Dimension. It was released as the third single from the album in September 1966, reaching number 36 on the Billboard Hot 100, but failing to chart in the United Kingdom. Upon its release as a single, the music press coined the term "space-rock" to describe it, although since then, this term has come to refer to a genre of rock music originating from 1970s progressive and psychedelic music.

"5D (Fifth Dimension)" is a song by the American rock band the Byrds, written by band member Jim McGuinn. It was released as a single in June 1966, and also included as the title track on the Byrds' third album, Fifth Dimension.