Notre Dame Heartthrob Sam Hartman Says He Can't Get Haircut, 'People Are Adamant'

You can catch Sam Hartman on a football field, in a weight room, or in a quarterback meeting ... but one place you won't find the former Notre Dame superstar is a barbershop -- 'cause he tells TMZ Sports he knows he simply cannot cut his luscious locks.

The Fighting Irish star spoke with us while out in Las Vegas for Super Bowl week ... and he explained that one thing he's learned since he's risen to stardom -- both on the field and off of it -- is that his hair has to be here to stay.

"People are adamant about that," Hartman said with a laugh. "And my mom likes it."

Of course, the 'do has certainly opened up a lot of doors for the 24-year-old in the past year or so. While his play on the field has obviously garnered him a lot of attention in the sports world -- his looks have turned him into an internet sensation.

In fact, an ad he just recently appeared in has already gained over 20 MILLION views on TikTok ... with most of the watchers droolin' over his mane in the comment section.

Hartman is clearly aware of it all ... telling us jokingly, "Shoutout to Mom for giving me the hair and giving me the good genetics."

But, the signal-caller has his eyes slated on far more than being a heartthrob ... he's gunning to make the NFL -- working his tail off this offseason so a team will select him in April's draft.