He played college football at Notre Dame, and was selected by the Bears in the second round of the 2020 NFL draft.

[4] As a true freshman at Notre Dame in 2017, Kmet played in all 13 games and had two receptions for 14 yards.

[6] In November, he announced that he would return to Notre Dame for his senior season rather than enter the 2020 NFL draft.

[7][8] On January 2, 2020, Kmet announced he would forgo his senior season at Notre Dame and would enter the 2020 NFL Draft.

[19] In Week 2 against the New York Giants, he recorded his first NFL reception with a 12-yard catch,[20] followed by his first touchdown four games later against the Carolina Panthers on a nine-yard score in the 23–16 victory.

[22] Bears offensive coordinator Luke Getsy was optimistic about Kmet, who did not catch a touchdown pass in 2021.

He commented on Kmet's versatility stating, "You talk about a guy that we hope can do a lot of different things.

We've put him in line and made him block the big boys up front too and I think the cool part about him is that he can do all of that stuff really well.