thumb|Evensong in York Minster, looking down the nave from beside the main altar; notice the choir arrangement into decani or Dean's side (as seen here, the left side) and cantoris or Cantor's side (here, the right side).
thumb|Stalls assigned to Decanus (left) and Praecentor (right) at Lincoln Cathedrals's St Hugh's Choir
Decani (; Latin: 'of the dean') and Cantoris (Latin: "of the cantor"; /kænˈtɔːrɪs/) are the sides of a church choir occupied by the Dean and the Cantor, respectively. The abbreviations "Dec." and "Can." are used. In English churches, the decani is typically in the choir stalls on the south side of the chancel, and the cantoris is on the left (liturgical North) side. There are some notable exceptions in the monastic cathedrals, where the senior cleric under the bishop was the prior; he often sat on the liturgical north.