Celebs gush over Reese Witherspoon's 19-year-old son on his birthday: ‘What a babe’

Reese Witherspoon has celebrated her son Deacon Phillippe's birthday in a sweet post, prompting a string of A-list celebrities to send their well-wishes too.

The actress, 46, shared a candid picture of her middle child, who turned 19 years old on Sunday, to her Instagram.

She captioned the image: "Big Birthday love for @deaconphillippe today! The guy who possesses the most joyful energy, endless drive, ambition and talent.

"And the biggest heart in the world. Could not be more PROUD of you...I love you, D!"

A number of high-profile names commented on the birthday post, which garnered more than 250,000 'likes'.

Read more: Reese Witherspoon channels her most confident self modelling own swimwear at 46

This included Witherspoon's friend and fellow actress Gwyneth Paltrow, who wrote: "What a babe."

Another Hollywood star Kate Hudson shared "HBD Deacon!" while comedian Chelsea Handler added "Love you, Deacon. You’re so sweet".

Who is Deacon Phillippe's father?

Witherspoon shares Deacon, along with 23-year-old daughter Ava, with her ex-husband actor Ryan Phillippe.

The former couple met at her 21st birthday party in 1997, and the pair went on to shoot the 1999 film Cruel Intentions together.

They married in 1999 but went on to separate in 2006, and finalised their divorce in 2008.

Phillippe, 48, rose to fame in the late 1990s with films including I Know What You Did Last Summer and 54.

After his split with the Legally Blonde star, he went on to have a son Kai, now 11, during a brief relationship with Pitch Perfect actress Alexis Knapp.

Read more: Reese Witherspoon opens up about postnatal depression

While Witherspoon's son Deacon received all the attention this weekend, the focus is usually on her lookalike daughter Ava.

The mother-of-three, who also has a 10-year-old son Tennessee with husband Jim Toth, recently insisted that she doesn't see the resemblance between her and the university student.

During an appearance earlier this month on NBC's Today with Hoda & Jenna show, she insisted: "She and I don't see it that much."

However, last month claims that the pair were the spitting image of one another were reignited when the Big Little Lies star posted a 'Daughter's Day' picture to Instagram.

Watch: Reese Witherspoon 'doesn't see the resemblance' between herself and her daughter