Collagna is a frazione, or borough, located within the municipality of Ventasso in the Province of Reggio Emilia. It is situated in the Italian region of Emilia-Romagna, approximately 90 kilometres west of Bologna and 50 kilometres southwest of Reggio Emilia.
Historically, Collagna functioned as an independent comune until January 1, 2016. On that date, it was merged with the neighboring localities of Busana, Ligonchio, and Ramiseto to form the current administrative structure of Ventasso.