Siri Kristine Nordby (born 4 August 1978) is a Norwegian football defender who played over fifteen years for Røa in Norway's Toppserien league.

Nordby started her career at Hosle IL, but quickly moved to neighbors Røa when she had to play for an all-girls team.

Nordby often played left- and right-back on the national team under coach Bjarne Berntsen, who is known to place his players in different positions.

She was also a member of the 2007 Women's World Cup squad that finished the tournament fourth as well as the 2008 Olympics team which was beaten by Brazil in the quarterfinals.

After the 2012 season she retired from top-flight football, but after a few months she joined Øvrevoll Hosle IL, whose women's team hunted promotion from the Second Division.