Lewis Morgan, Ryan Christie and Mikey Johnston scored the goals for Neil Lennon's side, who had already booked their place in the last 32. The Hoops will now be seeded, along with the other group winners and the four best-ranked teams dropping out of the Champions League.
Rangers are also well placed to qualify after an Alfredo Morelos double earned them a 2-2 draw with Feyenoord in Rotterdam. Steven Gerrard's team need a point at home to Swiss side Young Boys on matchday six to be sure of joining Celtic in the next round.