Reese Witherspoon Shares an Adorable Photo of Herself With Son Tennessee — Plus See More Cute Celebrity Kids!

What a precious mother-son moment!

Reese Witherspoon took to Instagram on Sunday, Jan. 3 to share a sweet snapshot of herself and her three-year-old son Tennessee — and we can't get over over how big the actress' little boy has gotten!

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Last day of vacation! 💖🌴☀️

A post shared by Reese Witherspoon (@reesewitherspoon) on

"Last day of vacation! ?," the 39-year-old Legally Blonde star captioned the adorable photo of the two swimming on a family getaway.

RELATED: Reese Witherspoon Steps Out With Her Lookalike Daughter Ava — See the Pics!

Reese and her hubby, Jim Toth — whom she tied the knot with in 2011 — welcomed Tennessee in September 2012. The actress is also a mom to daughter Ava, 16, and son Deacon, 11, from her first marriage to actor Ryan Phillippe.

Click through the gallery below to see more of Hollywood’s cutest kids!