Paris Hilton Throws 'Sliving Under the Sea' 1st Birthday Party for Son Phoenix — See the Photos!

The celebrity-packed birthday bash was held at Hilton's home on Saturday and featured guests including Rumer Willis, Kelly Osbourne and Lance Bass

Paris Hilton is celebrating her baby boy’s first birthday!

On Saturday, the reality TV star, 42, threw a lavish ‘Sliving Under the Sea’ themed birthday party for 1-year-old son Phoenix as stars, including Kelly Osbourne and Rumer Willis joined the celebrations at her home.

In videos posted from the party, Hilton's back yard was an underwater vision come-to-life as fish-shaped balloons and seaweed filled the patio. White seats shaped like coral with starfish cushions dotted around the space as music from Disney’s The Little Mermaid played on speakers.

Explaining the party theme in one clip, Hilton said — as she held Phoenix, who turned one on Jan. 16 — “It’s Phoenix’s first birthday and we have a ‘Sliving Under the Sea’ theme. I’m so excited.”

Related: Paris Hilton on Son Phoenix's 1st Birthday Party Plans Including Petting Zoo

“I’ve thrown amazing birthday parties my whole life,” she continued. “So to now be able to do this for my little boy is such a special memory.”

Hilton then said to Phoenix, “Are you ready for your birthday?” as she carried her baby boy out into the back yard to view the impressive decorations at the party, “Look, this is all for you! Look at this! Yay!” the mom of two added.

Among the guests seen at the party were Kelly Osbourne, who brought 13-month-old son Sidney along, Rumer Willis and nine-month-old daughter Louetta Isley, Lance Bass and 2-year-old twins Alexander and Violet, Kat Von D and son Leafar, 5, and model Jessica Hart.

The guests were joined by a host of furry friends at the bash including sheep, bunnies, baby goats, chickens — and a unicorn! — as a petting zoo was set up for them to enjoy. Hilton and Phoenix were seen in other footage with the kids stroking the animals as they sat together in a pen.

Related: Kathy Hilton Bursts into Tears as She Recalls Meeting Paris’ Son Phoenix, 1, for the First Time: 'So Beautiful'

Hilton shares son Phoenix and daughter London Marilyn, 2 months, with husband Carter Reum. The pair welcomed both children via surrogate. 

Hilton’s milestone party for Phoenix comes after posting a heartwarming birthday tribute to her baby boy earlier this month as she called him a “dream come true.”

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The mom of two shared a series of sweet snaps on Instagram as she wrote, "One year ago, a beautiful angel baby entered our lives, bringing so much love and happiness🥹🩵👶🏼✨.”

“My precious little one, you are more than a dream come true," Hilton continued. "You make my life complete🥰 Every day with you is a priceless gift, and I’m endlessly grateful to be your mommy. 🌟🥰."

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