The reality star - who revealed on Keeping Up With The Kardashians yesterday that she is expecting a baby girl - was the centre of attention at the party in Beverly Hills, E! News reports.
The luxurious bash, which began at 11.30am, saw guests tucking into a buffet of eggs, bacon, lox and bagels, pancakes and waffles.
They were handed mimosas to drink and could also fill up at the omelette station and dessert stop - which featured cotton candy, lollipops and strawberry shortcake.
Among the famous faces who attended the shower and were handed floral crowns - besides Kardashian's famous relatives - were Mel B, Kelly Osbourne, Maria Menounos and Kimberly Stewart.
Real Housewives star NeNe Leakes, Nicole Richie, trainer Tracy Anderson and Brittny Gastineau were among the other guests who were invited to the event.
Kourtney Kardashian and Khloe Kardashian were joined by their partners Scott Disick and Lamar Odom, while Kim's beau Kanye West arrived towards the end of the party - though he covered his face in his hoodie in an attempt not to be photographed.
Kardashian matriarch Kris Jenner reportedly gave a champagne toast at the party, with a source saying: "She gave a speech and said she couldn't believe her baby is going to be a mum."
Meanwhile, Khloe later told E! News that the shower had been "such a magical day", adding: "We are so happy to celebrate with Kim and Kanye West!"
Kim also seemed to enjoy the party, tweeting later: "WOW an amazng baby shower! So much luv there Thank u @KrisJenner @KourtneyKardash @KhloeKardashian Shelli & Allison Azoff 4 the magical day."
She added: "Truly such a special day. I honestly feel so blessed and filled with so much love!"
Keeping Up With The Kardashians airs Sundays on E! in the US and will premiere in the UK on July 7 at 10pm on E!