Behrens started his career in 2010 in the
Bremen-Liga, the fifth division of German football, for
Werder Bremen III. From 2011-2018, he played in the
Regionalliga, the fourth division of German football, for
SV Wilhelmshaven,
Hannover 96 II,
Alemannia Aachen,
Rot-Weiss Essen,
1. FC Saarbrücken. He made his
2. Bundesliga debut in 2018 with
SV Sandhausen. With Saarbrücken, he won both the 2016–17
Saarland Cup and
2017–18 Regionalliga Südwest. Behrens transferred to East Berlin-based
Bundesliga club
Union Berlin during the 2021 summer transfer window. On 16 September 2021, he scored his first goal in European competitions in a 3–1 defeat against
Slavia Prague in the
2021–22 Conference League. On the first matchday of the
2023–24 Bundesliga season, Behrens scored his first Bundesliga hat-trick, all being headers, on 20 August 2023 at the
Stadion An der Alten Försterei against
1. FSV Mainz 05 in a 4–1 home victory. On 20 September 2023, he made his
UEFA Champions League debut in a 1–0 defeat against
Real Madrid. On 31 January 2024, Behrens moved to
VfL Wolfsburg. In October that year, Wolfsburg fined Behrens for making a
homophobic comment during an autograph session, refusing to sign a
rainbow-themed Wolfsburg jersey. He later apologised, and the club reaffirmed its commitment to diversity and tolerance. Later that month,
FC St. Pauli fans protested his appearance with a “more love, less Kevin Behrens” banner. On 15 July 2025, Behrens signed a two-season contract with
Lugano in Switzerland. On 9 January 2026, during a friendly match against
Viktoria Plzen, during play, Behrens shoved teammate
Georgios Koutsias to the ground and verbally berated him, causing teammate
Uran Bislimi to intervene between the players. After the incident, Behrens requested to be substituted and the club issued a statement after the friendly in which they condemned the confrontation and announced an internal investigation into the incident. ==International career==