On the Third Day is the third studio album by Electric Light Orchestra (ELO), and the first to be recorded without input from Roy Wood. It was released in the United States in November 1973 by United Artists Records, and in the United Kingdom on 14 December 1973 by Warner Bros. Records. From this album on, the word The was dropped from the band's name. The album was reissued on 12 September 2006.

The Electric Light Orchestra (ELO) are an English rock band formed in Birmingham in 1970 by songwriters and multi-instrumentalists Jeff Lynne and Roy Wood with drummer Bev Bevan. Their music is characterised by a fusion of pop and classical arrangements with futuristic iconography. After Wood's departure in 1972, Lynne became the band's sole leader, arranging and producing every album while writing nearly all of their original material. From this point until their first break-up in 1986, Lynne, Bevan, and keyboardist Richard Tandy were the group's only consistent members.