Bjoergen pushed the pace much of the way, pulling away from her rivals midway through the freestyle portion of the race and was never threatened over the last kilometers.
She entered the ski stadium with a comfortable lead, raising her hands in the air to salute the flag-waving Norwegian fans as she paraded down the final straightaway.
Anna Haag, of Sweden, was a surprising second after winning a three-way sprint for the silver medal, finishing 8.9 seconds behind. Pre-race favorite Justyna Kowalczyk, of Poland, took the bronze after beating Kristin Stoermer Steira, of Norway, in a photo finish for her second medal of the game.
Charlotte Kalla of Sweden, the gold medalist in the 10K freestyle race, got tangled up and fell midway through the classical section. She got right back up to join the leaders, but soon fell back and was 28 seconds behind going into the freestyle portion.
ICE DANCING: World champions Oksana Domnina and Maxim Shabalin, of Russia won the compulsory portion of ice dance.
Their 9.0 interpretation mark helped give them 43.76 points for an expressive program to the tango romantica. That is 1.02 points ahead of Canada's Tessa Virtue and Scott Moir heading into Sunday's original dance, the second of three parts in the ice dancing event.
Two-time American champions Meryl Davis and Charlie White are third with 41.47 points, followed by 2006 Olympic silver medalists Tanith Belbin and Benjamin Agosto of the United States with 40.83.
Ice dance competition concludes Monday night with the free dance.
HOCKEY: Daniel Alfredsson scored twice and defending gold medalist Sweden avoided a monumental upset against outmanned Belarus like that in 2002, winning 4-2 Friday for its second successive Olympic hockey victory.
Daniel Sedin, playing in his NHL home arena, and Johan Franzen, part of what might be hockey's best fourth line, added goals as Sweden took what looked to be a safe 3-0 lead. But Belarus, despite generating few offensive rushes and scoring chances, got two goals from Dmitri Meleshko to make it close.
CURLING: The U.S. men have their first Olympic victory, beating France 4-3 after four consecutive losses.
Regular skip John Shuster was benched for the match because of his poor shot-making. Alternate Chris Plys was promoted to the skip spot and vice skip Jason Smith threw last rock.
The women finally won, too. Skip Debbie McCormick bumped out a Russian stone with her last rock, giving the U.S. a 6-4 victory -- its first after an 0-3 start.