As a child he was a keen footballer, before focusing squarely on golf at the age of 13.

He enjoyed a lot of success as a junior, and was the recipient of the Annika Sörenstam Trophy for winning the Swedish Teen Tour Order of Merit in 2016. He also represented Sweden at the 2017 European Boys' Team Championship and also won the Fairhaven Trophy that same year.

In 2018 he made his DP World Tour debut as an amateur at the Nordea Masters, finishing T34. He then joined Texas Tech in 2019, and helped Sweden to victory that same year at the European Amateur Team Championship.

A year later, he played on the Nordic Golf League in 2020 as collegiate golf was paused due to the Covid-19 pandemic, winning twice.

He went on the claim the individual title at the 2022 Big 12 Men's Golf Championship and was named the Ben Hogan Award winner as the best college golfer in the United States. He Rose to number one on the World Amateur Golf Ranking that year, in September 2022.

Went back-to-back at the Big 12 Men's Golf Championship in 2023 as he finished eight strokes ahead of second place and his winning total of 15-under broke the event's scoring record of nine under par, set by Rickie Fowler in 2008. It earned him the Ben Hogan Award for a second time in 2023, joining Jon Rahm as the only other player to receive the accolade twice.

He would go on to secure his status on the PGA TOUR through the 2024 season after finishing on top of the 2022-23 PGA TOUR University rankings, and turned professional in June 2023.

Åberg won his maiden DP World Tour title at the 2023 Omega European Masters and received a Captain's Pick for Luke Donald's Ryder Cup side the following day, making history as the first player to play at a Ryder Cup before making an appearance in a Major Championship.

Formed a formidable partnership with fellow Scandinavian Viktor Hovland at Marco Simone as they won both their foursomes matches, including a record 9&7 defeat of World Number One Scottie Scheffler and five-time Major winner Brooks Koepka. Returned two points on debut as he helped Europe regain the Ryder Cup.

Ended a remarkable 2023 with his first PGA TOUR victory at the RSM Classic, becoming the first golfer in history to turn professional and win on both the DP World Tour and PGA TOUR in the same year.