The draw was made on Wednesday afternoon and Saints were set to face Racing 92 and Ulster or Connacht and Bordeaux-Begles.
They were placed in Pool A, meaning they will face trips to Paris and Belfast in December and January.
Saints last faced Ulster back in April, losing to them in a Challenge Cup quarter-final at Franklin's Gardens.
But they do have good memories of their last competitive trip to Belfast back in December 2012, when the black, green and gold grabbed a memorable European win.
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As for Racing, Saints have faced them numerous times during the past decade, but they have not played against the Parisians since December 2015.