The pool stage fixtures were announced on Friday afternoon, with Saints kicking things off in Europe's top tier competition.
They will then travel to Dublin to face Leinster at the RDS Arena on Saturday, December 19 (kick-off 1pm).
Leinster come to the Gardens on Friday, January 15 (kick-off 5.30pm) before Saints finish their pool stage campaign in Bordeaux on Saturday, January 23 (kick-off 2pm).
All of the matches will be televised live on BT Sport.
Saints' 2020/21 Champions Cup fixtures
Friday, December 11: Home to Bordeaux, 5.30pm.
Saturday, December 19: Away to Leinster, 1pm.
Friday, January 15: Home to Leinster, 5.30pm.
Saturday, January 23: Away to Bordeaux, 2pm.