Hjalmar Stefanus Mellander (14 December 1880 – 3 October 1919) was a Swedish track and field athlete. He competed in the 800 m, long jump, javelin throw and ancient pentathlon at the 1906 Intercalated Games.
At the 1906 Intercalated Games (Olympic Games), he finished fourth in the long jump and javelin throw. He won the pentathlon event, which consisted of standing long jump, Greek-style discus throw, javelin throw, 192 m sprint and Greco-Roman wrestling.[1][6]