Lydia Boucher (28 February 1890 – 5 March 1971) was a Canadian composer, music educator, and nun.
Most of her works are sacred and many of them were published by L'Édition Belgo-Canadienne, Musica Enrégistré, and Éditions canadiennes.
Some of her other notable pieces include the piano works Trois Préludes (1928–30) and La Ronde des aiguilles (1950), and the Alleluia for organ (1958).
[citation needed] Boucher was active as a teacher of piano, voice, violin, and organ from 1909 to 1969.
She taught at several different schools and institutions during her 60-year teaching career, including the Maison-Mère Mont-Ste-Anne in Lachine and the École de musique Wilfrid-Pelletier in Montreal.