The Belarusian exemplified consistency in 2025 and arrives for the November 1-8 tournament having retained her US Open title in September, after finishing runner-up to Madison Keys at the Australian Open and Coco Gauff at Roland Garros.
The only Grand Slam final she failed to reach was at Wimbledon, where Iga Swiatek defeated Amanda Anisimova.
"It's easier when you qualify early in the season but I'm super excited," said Sabalenka, who punched her ticket to the WTA Finals in July.
"Honestly I cannot wait to get back. I love that place, I love to play there, and I hope that this year I can do better than I did last year."
Martina Navratilova said the 27-year-old's sustained high-level performances made her the favourite in the eight-player line-up.
"Her consistency is not to be underestimated," 18-times Grand Slam singles champion Navratilova told the WTA website.
"There are so many players you can lose to these days, you have to be on your game at all times, and she was.
"She's the heavy favourite on any surface but particularly on medium-pace hard courts where you get a solid bounce and good footing.
"It's fast enough for her to do damage and slow enough for her to prepare for her shots. She's deadly on this stuff."
World number two Swiatek failed to capture a fourth successive French Open trophy in June but excelled on grass a month later to win her first Wimbledon title.
The 24-year-old Pole, whose season stalled late last year when she served a month-long doping ban following a positive test for trimetazidine due to contaminated sleep medication, has won hard-court titles in Cincinnati and Seoul this season and has been pleased with her "solid performances" this year.
"Winning Wimbledon was a unique experience, and then also Cincinnati and Seoul," 2023 WTA Finals champion Swiatek said.
"Overall, I would assess my season as a journey of growth, where I've learned a lot of lessons especially since the end of the last year."
Make a statement
Defending champion Gauff is the only other contender to have previously won the WTA Finals title. The American experienced a dip in form following her Paris triumph this year but has turned the corner with a win in Wuhan and a run to the Beijing semis.
Anisimova is another one to watch as the debutant looks to make up for two Grand Slam final defeats - at Wimbledon and the US Open - with the WTA Finals title and a big chunk of the $15.5 million prize money on offer.
Former women's number one Tracy Austin believes the American will be a force in Riyadh.
"With her recent victory in Beijing followed by two weeks off, the two-times WTA 1000 champion and two-times Grand Slam finalist is rested, match-tough and keen to make a statement," she told Tennis Channel.
Keys is another big hitter who can pose a massive threat on hardcourts, like she did in Melbourne at the start of the year to stun Sabalenka and win her a first Grand Slam.
Others contenders in Saudi Arabia include former WTA Finals runner-up Jessica Pegula, the late-surging Elena Rybakina and twice Grand Slam finalist Jasmine Paolini.
Unlike the last two seasons, the year-end world number one ranking will not be decided at the tournament with Sabalenka holding an unassailable lead.
The season finale also features the top eight doubles teams in the world.
WTA Finals singles draw
Steffi Graf Group:
Aryna Sabalenka
Coco Gauff
Jessica Pegula
Jasmine Paolini
Serena Williams Group:
Iga Swiatek
Amanda Anisimova
Elena Rybakina
Madison Keys