Tlaib, also a Democrat, led the booing at an event in Iowa on Friday in response to Clinton saying in a documentary that "nobody likes" presidential hopeful Bernie Sanders, who had also contested in 2016 when the former First Lady was in the running, reports the BBC.
Tlaib later said that she had allowed her feelings about Clinton's remarks "to get the best of me".
"I know what is at stake if we don't unify over one candidate to beat (President Donald) Trump and I intend to do everything possible to ensure that Trump does not win in 2020," she tweeted on Saturday.
"In this instance, I allowed my disappointment with Secretary Clinton's latest comments about Senator Sanders and his supporters get the best of me. You all, my sisters-in-service on stage, and our movement deserve better."
The Michigan representative was taking part in a panel event with fellow Democratic Congresswomen Pramila Jayapal and Ilhan Omar, held at a folk music concert in Iowa on Friday.
When the moderator brought up the escalating feud between Clinton and Senator Sanders, members of the audience began to boo, the BBC report said.
The moderator interrupted and said: "We're not going to boo, we're classy here," to which Tlaib replied: "No, no, I'll boo."
"You all know I can't be quiet. No, we're going to boo. That's all right, the haters will shut up on Monday when we win," she added.
Monday's caucuses will be the first formal test this year of Democratic voters' preferences. Senator Sanders is the frontrunner, with a slight lead ahead of his nearest rival, former Vice President Joe Biden.
( With inputs from IANS )