Pärson thereby ended years of rumours about her sexuality and became the latest Swedish sports star to go public.
"I am tired of being someone else and of playing a game. I owe it to myself and especially to Filippa to tell the truth," Pärson said while hosting a programme on Sveriges Radio.
The 31-year-old Olympic champion, who ended her career and retired following the World Cup earlier this year in Schladming, Austria, has for years faced rumours about her personal life.
"The time of rumours is now over," she said during the pre-recorded nearly 90-minute programme.
Pärson told listeners she had never thought she would fall in love with a woman, but that after she met Filippa, 39, in 2005 their friendship had gradually developed into something more.
"I had never intended to fall in love with a woman. Never thought that my heart could beat so fast for a woman. I was insanely in love," she said.
She wrapped up the programme with another surprise announcement, admitting she had lied in interviews after her retirement when she told reporters she did not know what she would do going forward.
"I have known for almost nine months what I will do in the future. I am going to be a mother," she said.
Pärson, who made her debut in 1988 at the World Cup in Switzerland, took 19 championship medals, 42 World Cup victories, and two overall World Cup titles in 2004 and 2005.
She also won six Olympic medals -- slalom gold at the 2006 Turin Games, a giant slalom silver in the 2002 Salt Lake City Games, and four bronzes (slalom in 2002, combined and downhill in 2006, and super-combined in 2010.)
Pärson's revelation comes soon after Anton Hysén (son of former Liverpool legend Glenn) was heralded for becoming the first openly gay Swedish footballer, and former high-jumper Kajsa Bergqvist said that she was bisexual.