Pärson's 39-year-old partner Filippa gave birth to the baby boy on Wednesday.
"Early yesterday morning (Wednesday) the most beautiful little boy in the world arrived. I don't think I could be happier," said the former Olympic champion, who also published a photo of the newborn.
The 31-year-old, who retired following the World Cup earlier this year, has for years faced rumours about her personal life, before revealing on Swedish radio last month that she was in a relationship with a woman.
"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 revealed while hosting a programme on Sveriges Radio in late-June.
Pärson, who made her debut in 1988 at the World Cup, 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.)