Gyda Ellefsplass Olssen (born November 16, 1978 in Elverum) is a Norwegian sport shooter.
At age twenty-nine, Olssen made her official debut for the 2008 Summer Olympics in Beijing, where she competed in two rifle shooting events.
She placed thirty-fourth out of forty-seven shooters in the women's 10 m air rifle, with a total score of 391 points.
Nearly a week later, Olssen competed for her second event, 50 m rifle 3 positions, where she was able to shoot 195 targets in a prone position, and 190 each in standing and in kneeling, for a total score of 575 points, finishing only in twenty-seventh place.