Raonic's victory over Federer in the quarter-finals of the Paris Masters event on Friday helped secure the Canadian his first-ever spot in the season-ending tournament, which begins Sunday in London for the top eight men's players in the world.
The other players in Group B along with Raonic and Federer are Andy Murray and Kei Nishikori.
Group A is fronted by two-time defending champion Novak Djokovic, who defeated Raonic in the final in Paris. The world's top player will be joined by Australian Open champion Stan Wawrinka, U.S. Open winner Marin Cilic and Tomas Berdych.
Djokovic, this year's Wimbledon champion, is unbeaten on indoor courts the past two years and is vying with Federer for the year-end No. 1 ranking.
French Open champ Rafael Nadal is skipping the tournament because of appendicitis.