Sagström made her professional debut at the 2015 Helsingborg Open on the Ladies European Tour in Sweden in September and earned her first pay-check.

After victories at both the Chico Patty Berg Memorial in Fort Myers, Florida, and the Self Regional Healthcare Foundation Women's Health Classic in Greenwood, South Carolina, Sagström led the tour's money list race by a wide margin, earning a spot in the LPGA 2017 rookie class.

[6] She was selected as a captain's pick by Annika Sörenstam to the 2017 European Solheim Cup team and finished the 2017 LPGA Tour season 49th on the Order of Merit.

In 2022, Sagström recorded four consecutive top-10 finishes, including T3 at the DIO Implant LA Open and the Cognizant Founders Cup, to rise into the top-30 of the Women's World Golf Rankings for the first time.

In the 2022 Women's British Open at Muirfield she shot a day-low 65 in round two to share second place with eventual winner Ashleigh Buhai.

[10] With the finish, Sagström surpassed the $4 million mark in career earnings and climbed to 109th on the LPGA all-time money list.