Serena Williams and her husband, Alexis Ohanian, are getting into the holiday spirit with a little local theater — showing face in a ballet play … one that their daughter is in too.

TMZ has obtained photos of the couple onstage Sunday during a production of “The Nutcracker” — which was being put on by a ballet school near Palm Beach Gardens, FL … where this play was going down at a local venue, with the little ones taking the lead.

Eyewitnesses tell us some adults made appearances as well … including Serena and Alexis, whom we’re told played guests at a party during one scene. They were definitely in character.

You can see Mama and Papa Bear dressed in full costumes as they acted out their parts — this while the other kid actors/performers stood around and welcomed them onstage. It looks like a fancy pretend get-together, ’cause SW did a sweet little curtsy next to her hubby.

This Sunday matinee wasn’t the only performance they did BTW — we’re told they did their thing for Saturday’s show as well. Super cute obviously, and it just goes to show … Serena and Alexis are very involved in their children’s lives.

As you know … Serena and Alexis got hitched in 2017 a couple months after they had their first daughter — who’s about 6 years old or so right now, and who was in this play.