Diary is the debut solo album by American jazz guitarist and composer Ralph Towner, recorded over two days in April 1973 and released on ECM later that year.

[1] The AllMusic review by David R. Adler awarded the album 3 stars, stating: "It's a solo performance with a twist: Towner plays not only 12-string and classical guitars, but also very competent piano.... Towner accompanies himself via overdubs, playing both guitar and piano for an effect vaguely reminiscent of Bill Evans' Conversations with Myself.

"[2] All tracks are written by Ralph Towner, except where noted.