Frank Willenborg is a German football referee born in Osnabrück, Germany on 10 February 1979. He made his Bundesliga debut on 20 September 2016. Willenborg is a veteran Bundesliga referee and teacher from Osnabrück. He is part of the current Bundesliga officiating pool and is regularly relevant for pre-match analysis, appointment previews and VAR-focused discussion.
In the 2025/26 Bundesliga season, Willenborg has officiated 8 league matches, averaging 20.63 fouls, 0.38 penalties, 3.75 yellow cards and 0.13 red cards per game. Those numbers point to a balanced but firm profile, with a solid middle ground in disciplinary terms. For The VAR Verdict, that statistical snapshot helps readers understand the disciplinary threshold and general tone he has shown this season.