Ms Lahren, 25, known for her outspoken conservative views, was at a restaurant in Minneapolis with her parents on Sunday when another diner tossed a glass of water on her.
She had reportedly been involved in a confrontation with a group of customers.
Footage from the incident circulating on social media showed Ms Lahren leaning over a table, apparently in the middle of a heated exchange.
Another video showed a woman throwing a drink at Ms Lahren as she walked out of the restaurant.
Whoever threw this drink at Tomi Lahren, thank you pic.twitter.com/RJE8xTDMZ3— I Luh God ✨ (@aVeryRichBish) May 21, 2018
Ms Lahren appeared on Fox & Friends on Wednesday, claiming a group of diners around her age threw the water and "chanted profanities" at her. She called the incident “embarrassing.”
"I was actually with both my parents and we were enjoying brunch," she said.
"Unfortunately there was a group of people probably around my age that thought it would be funny to throw water at me and then start chanting profanity and, again, not something that I'm not used to, but [it was] really disheartening."
She added that said both she and her mother got "wet".
"This is something that was embarrassing, at the end of the day I'm a person too, but I'm tough, my family is tough, we can handle it.
"I think that those that threw profanity and water and were applauding and laughing about it, wanted to get their 15 minutes of fame by making a video of me.
"Looking back, those are the people that will be embarrassed by the action. Their parents raised them better, furthermore, you don't have to like me but you don't have the right to throw things at me."
Shortly after her appearance, Mr Trump tweeted: “Everybody is with Tomi Lahren, a truly outstanding and respected young woman!”
Everybody is with Tomi Lahren, a truly outstanding and respected young woman! @foxandfriends— Donald J. Trump (@realDonaldTrump) May 23, 2018
Ms Lahren responded by re-posting the tweet with an American flag on her own account.
Witness Devan Madison told The Blast that his friend was serving Ms Lahren and her mother at the restaurant.
"My friend told me she [Tomi] was extremely rude and had a big attitude," Mr Madison said.
He added that the restaurant started cheering after the water had been thrown.
A clip of incident was shared online, filmed by Snapchat user Jasmine Kohler, who said "I did it lol".
Captions on the footage said: "Throws a drink on Tomi Lehren hahahaha. Thanks for the screenshots I did it lol."
A bouncer seen in the video, Jeremy Jackson, said Ms Lahren claimed that the group sitting at the table was "scowling at her" as she made her way out of the restaurant.
Ms Lahren is a conservative commentator on the Fox News Channel. She is known for making provocative statements.
She first rose to fame in 2015, when she hosted a show on the far-right One America News Network.