Japan's Osaka, who counts the 2018 and 2020 US Opens among her four Grand Slam titles, returned to competition in January after the birth of her daughter and has advanced to the third round or better at four WTA 1000 events this season.
Canada's Andreescu, the 2019 champion, returned to action this year after missing nine months due to a back injury and reached the French Open third round in her first event back.
For Swiss Wawrinka, who won the most recent of his three Grand Slam titles at the 2016 US Open, the wildcard allows him to make his 72nd main draw appearance in one of the game's four blue-riband events, which puts him fifth on the all-time list.
Austrian Dominic Thiem, the 2020 champion who announced this year that he will retire following the 2024 season due to a wrist injury, was also given a wildcard.
The US Open will held from August 26th-September 8th in New York.