Steen Fladberg Nielsen (born 11 October 1956) is a Danish badminton player, noted for his speed of foot, who excelled during the 1980s.

Though a strong international level singles player, his biggest achievements came in doubles.

[1] Fladberg won the gold medal at the 1983 IBF World Championships in men's doubles with Jesper Helledie, defeating Mike Tredgett and Martin Dew 15–10, 15–10 in the final.

He was a silver medalist at the same tournament in mixed doubles with Pia Nielsen.

Fladberg married the former Danish badminton player Kirsten Larsen.