Heidi Weng born 20 July 1991 is a Norwegian cross-country skier and fell runner.
In cross-country skiing her best individual World Cup finish is a third place in Lahti in March 2012. She has won three gold medals at the Junior World Championships, two in relay and one in pursuit.
She is a Norwegian senior champion in fell running in 2010, and placed fourth at the World Junior Championships in the same year. She is also a Norwegian junior champion in cross-country running.
She hails from Ytre Enebakk, but represents the club IL i BUL.
Weng won the bronze medal at the skiathlon event at the 2014 Winter Olympics in Sochi.