He played college football for the Iowa Hawkeyes and was selected by the 49ers in the fifth round of the 2017 NFL draft.

[4] His father, Bruce Kittle, was a four-year letterman and co-captain of the 1982 Rose Bowl squad at Iowa and is a former college football coach.

His mother, Jan Krieger, is in the Iowa Girls’ High School Athletic Union Hall of Fame and played softball and earned All-America honors in basketball at Drake University.

[2][7][8] As a freshman, Kittle had a limited role behind senior C. J. Fiedorowicz, junior Ray Hamilton, and sophomore Jake Duzey.

[15] As a senior in the 2016 season, Kittle headlined a tight end unit that contained junior Peter Pekar and freshman Noah Fant.

[20] On March 27, 2017, Kittle participated at Iowa's Pro Day, along with C. J. Beathard, Desmond King, Jaleel Johnson, Greg Mabin, Riley McCarron, and four other prospects.

[21] At the conclusion of the pre-draft process, Kittle was projected to be a third or fourth round pick by NFL draft experts and scouts.

He was ranked the fifth best tight end prospect in the draft by NFL analyst Mike Mayock, sixth best by NFL analyst Gil Brandt, and was ranked the eighth best tight end by NFLDraftScout.com.

[28] Throughout training camp, he competed against Garrett Celek, Vance McDonald, Logan Paulsen, Blake Bell, and Cole Hikutini for the job as the starting tight end.

[29] Kittle made his NFL debut in the 49ers' season-opener against the Carolina Panthers and caught five passes for 27 yards in a 23–3 loss.

He caught his first NFL reception on a 13-yard pass from Brian Hoyer on the first drive and was tackled by Panthers' safety Mike Adams.

[30] On October 8, 2017, Kittle made seven receptions for 83 yards and his first NFL touchdown during a 26–23 overtime loss to the Indianapolis Colts.

[31] During a Week 9 matchup against the Arizona Cardinals, Kittle caught three passes for 27 yards, before leaving the 20–10 loss with a leg injury.

He finished the regular season with his first 100-yard receiving game in Week 17 against the Los Angeles Rams.

[35] During Week 4 against the Los Angeles Chargers, Kittle recorded an 82-yard touchdown reception as part of a 125-yard performance as the 49ers narrowly lost by a score of 29–27.

[38] During the season finale against the Rams, Kittle broke Travis Kelce's single-season receiving yards record for a tight end, less than an hour after Kelce broke the record, on a 43-yard touchdown and finished the season with 1,377 yards.

[50] In Super Bowl LIV against the Kansas City Chiefs, Kittle caught four passes for 36 yards during the 31–20 loss.

[53] After missing two games due to a knee injury,[54] Kittle returned in Week 4 against the Philadelphia Eagles on Sunday Night Football, finishing with 183 receiving yards and a touchdown as the 49ers lost 20–25.

[58] In an injury-riddled season, Kittle finished with 48 receptions for 634 receiving yards and two touchdowns in eight games.

[62] On November 8, in his return game, Kittle caught six passes for 101 yards and a touchdown in a loss to the Cardinals.

[79] In Super Bowl LVIII, he suffered a shoulder injury during the third minute of overtime and went to the locker room for the remainder of the game.

[102][103][104] Kittle is a fan of professional wrestling, having cited Penta as his favorite wrestler, and uses his "Cero Miedo" (Spanish for "No Fear") taunt when he gets a first down.