Andy Murray will open his ATP World Tour Finals campaign against Marin Cilic on 14 November.
The Briton hopes to win the season-ending event for the first time and end 2016 at the top of the rankings, having replaced Novak Djokovic on Monday.
Murray will take on Stan Wawrinka, Kei Nishikori and Cilic in the round-robin stage at London’s O2 Arena.
Second seed Djokovic will face Milos Raonic, Gael Monfils and Dominic Thiem in the other group.
Djokovic will play Austria’s Thiem in the opening singles match, not before 14:00 GMT on Sunday, 13 November, while Murray plays Cilic not before 20:00 the following day.
Murray needs to at least match Djokovic’s performance in London to ensure he keeps hold of the top ranking until the start of next season, but he has been handed a tough draw.
|ATP World Tour Finals group stage|
|John McEnroe Group||Ivan Lendl Group|
|1. Andy Murray (GB)||2. Novak Djokovic (Ser)|
|3. Stan Wawrinka (Swi)||4. Milos Raonic (Can)|
|5. Kei Nishikori (Jpn)||6. Gael Monfils (Fra)|
|7. Marin Cilic (Cro)||8. Dominic Thiem (Aut)|
The Scot, 29, has a winning record against all three opponents in the John McEnroe Group but has suffered recent defeats against each of them.
Murray has lost three of his last four matches against Wawrinka, including in last year’s group stage, although he did beat the Swiss in their only meeting this year in the French Open semi-finals.
He also lost last time out against Nishikori, in the US Open quarter-finals, and Cilic, in the Cincinnati final.
Djokovic has never lost to Raonic, Monfils or Thiem, racking up a total of 23 wins against the three.
Murray has yet to make it past the semi-finals at the ATP’s showpiece tournament but will arrive in confident mood after winning the Paris Masters title on Sunday, 24 hours after confirming his new number-one status.
“Yesterday was a great day, today has just been a normal day at home with the family,” Murray said after the draw.
“Once you’re out on the court, you don’t think about your ranking. You’re playing against the top eight players in the world. I look forward to getting out there and playing at the O2.
“I’ll try and take a few days rest now, start hitting again on Thursday. I need a few days’ break.
“It will be one big push for all the guys. Everyone has played a lot of tennis and hopefully everyone can play well.”
Jamie Murray and Brazil’s Bruno Soares will play Treat Huey and Max Mirnyi in the doubles event not before 18:00 on Sunday.