A chansonnier is a handwritten or printed book that contains a collection of songs, known as chansons. These songs can be performed with multiple voices (polyphonic) or a single voice (monophonic). Some chansonniers only include the words of songs, not the music, such as the Cancioneiro da Vaticana and Cancioneiro da Biblioteca Nacional, which hold many Galician-Portuguese lyrics.

The most important chansonniers include the words, poems, and songs of medieval musicians called troubadours and trouvères. Before 1420, many song-books included both religious and secular music, except for those containing the works of Guillaume de Machaut. Around 1420, religious and secular music were separated into different books. Large choirbooks held religious music, while smaller chansonniers were used privately by people with high social status. Chansonniers were mainly created in France but also in Italy, Germany, and the Iberian Peninsula.