West asked for her hand in marriage in front of their friends and family at baseball stadium AT&T Park in San Francisco, Calif. He rented out the stadium specifically for the proposal.
A 50-piece orchestra played Lana Del Rey's "Young and Beautiful" before the band serenaded Kardashian with West's chart-topping single "Knock You Down."
West then proceeded to get down on one knee while he presented Kardashian with a 15-carat diamond ring by jeweler Lorraine Schwartz. Simultaneously, fireworks and Roman candles exploded in the sky.
A sign above the playing field also flashed the message, "PLEEEASE MARRY MEEE!!!"
The couple started dating last year and welcomed their first child, daughter North, in June.
Kardashian has been married twice before. She divorced Damon Thomas in 2004, and later married NBA basketball player Kris Humphries in 2011. Although their lavish wedding was televised, it didn't last. They split after just 72 days of marriage.
West, meanwhile, is currently on his "Yeezus" tour.