Don Angelo Grillo O.S.B. (1557–1629) was an Italian early baroque poet who published under the pen name Livio Celiano. His madrigal texts were set by Monteverdi, Filippo Bonaffino, Orazio Vecchi, Luca Marenzio, Salamone Rossi and others.
The close relationship between Grillo and Monteverdi appears in their correspondence, which began about 1610 and continued until the poet's death in 1629.
- Denis Stevens Monteverdi in Venice p56 2001