Younger Than Yesterday is the fourth studio album by the American rock band the Byrds and was released on February 6, 1967 on Columbia Records. It saw the band continuing to integrate elements of psychedelia and jazz into their music, a process they had begun on their previous album, Fifth Dimension. In addition, the album captured the band and record producer Gary Usher experimenting with new musical textures, including brass instruments, reverse tape effects and an electronic oscillator.

The album also marked the emergence of the band's bass player Chris Hillman as a talented songwriter and vocalist. Prior to Younger Than Yesterday, Hillman had only received one shared writing credit with the Byrds, but this album saw him credited as the sole composer of four songs and a co-writer of "So You Want to Be a Rock 'n' Roll Star". Byrds expert Tim Connors has remarked that two of Hillman's compositions on Younger Than Yesterday exhibited country and western influences and thus can be seen as early indicators of the country rock experimentation that would feature—to a greater or lesser degree—on all of the Byrds' subsequent albums.