Granath's parent club is IF Tymer. He joined Skövde AIK as a youngster.[3] Between 2015 and 2018, Granath played for the first team in both Division 2 and Division 1.
In January 2019, Granath was recruited by Degerfors IF, where he signed a two-year contract.[4] Granath made his Superettan debut on 31 March 2019 in a 4-1 win over Syrianska FC.[5] He played 29 league games and scored three goals in the 2020 season, as Degerfors IF were promoted to Allsvenskan for the upcoming season. In December 2020, Granath extended his contract at Degerfors by three years.[6]
After the relegation to Superettan in 2023 for Degerfors IF, Gustav chose to leave the club on a free transfer.[7]
On February 13, 2024, it was confirmed that Granath had joined Danish Superliga side Vejle Boldklub. Granath signed a deal until the end of the season, with a built-in option to extend the partnership by two years.[8] Granath left the club when his contract expires at the end of June 2024.[9] He never made his official debut for the club and only managed to sit on the bench in a single game for Vejle due to injuries.
On July 6, 2024, Västerås SK confirmed that Granath joined the club on a contract until the end of the year.[10]
Private life
Gustav Granath hails from the small hamlet Timmersdala, where he started his career in tiny IF Tymer. Gustav Granath described his youth as "perfect", with football being about the only available activity in the locale. His brothers Viktor and Villiam are footballers as well. All three played simultaneously for Skövde AIK in 2015, together with their first cousin Philip Granat. The three brothers are also first cousins once removed of footballer Jonas Granath.[11][12]