Danilova won a total of eleven medals at the FIS Nordic World Ski Championships, including four golds (4 x 5 km: 1995, 1997, 1999, 2001), four silvers (5 km: 1999, 10 km: 2001, 15 km: 2001, 30 km: 1999), and three bronzes (5 km + 10 km combined pursuit: 1995, 5 km: 1997, 5 km + 5 km combined pursuit: 2001). She also won the 30 km event at the Holmenkollen ski festival in 2000.
Danilova won three medals at the 1998 Winter Olympics in Nagano, with a gold in the 15 km classical and the 4 x 5 km, and a silver in the 5 km + 10 km combined pursuit.
In 2002 she again participated in the cross country skiing events at the 2002 Winter Olympics. Danilova won two medals with a gold in the 5 km + 5 km combined pursuit and a silver in the 10 km classical. However, she was one of three cross-country skiers (together with Johann Mühlegg and Larisa Lazutina) who was disqualified after blood tests indicated the use of darbepoetin, a drug intended to boost red blood cell production.
In February 2004 the I.O.C.stripped Danilova's medal awards following a Court of Arbitration for Sport (CAS) ruling in December, 2003. The results were amended accordingly. As a result of the use of the banned substance, Olga Danilova received a two-year ban by the International Ski Federation in 2002.