Nilsson signed his first professional contract with GIF Sundsvall and later made 30 appearances, scoring two goals for the club. He later signed with IF Elfsborg and amassed over 92 appearances during his three years with the club.
After his time with IF Elfsborg, Nilsson joined Arminia Bielefeld who signed him to a three-year contract to play in the 2. Bundesliga league. Nilsson wasted no time in Germany, playing a major role in the club winning the 2. Bundesliga title and gaining promotion to the Bundesliga in 2020.
In his first year in the German topflight, Nilsson anchored Arminia Bielefeld’s defense as they battled to remain in the first division. He made a total of 89 appearances for Arminia Bielefeld, scoring four goals for the club – two of which came in the final three games of his final Bundesliga season.
Nilsson has also represented his national team Sweden at various levels and has been called up frequently since making his senior debut in a 1-1 draw against Estonia on January 6, 2016. He has totaled over 29 appearances for his country.
