K-ON!! Original Soundtrack Vol.1 is the first "Original Soundtrack" (OST) of the second season of the anime K-ON!. The album contains 18 instrumental songs and two (Amefuri and Usagi to Kame) with vocals, sung by Yui Hirasawa's and Ui Hirasawa's respective voice actresses Aki Toyosaki and Madoka Yonezawa. The songs are used as background music during the second season of the anime. The album was released on 21 July 2010 in Japan by Pony Canyon.
With the exception of tracks 19 and 20, the whole album was composed, arranged and recorded by Hajime Hyakkoku.