Career Accolades
- Team Captain (2018, 2019)
- All-Pac-12 second team (2018)
- Two-time Pac-12 All-Academic honorable mention (2017, 2018)
As a Senior (2019)
- Team Captain
- Played in and started five games
- Was 102 of 167 passing for 1,038 yards and six touchdowns
- Had 24 rushing yards on 18 attempts
- Passed for 199 yards and a touchdown at UCF to move to ninth all-time in Stanford history for passing yards, surpassing Trent Edwards
- Finished 13-for-44 passing with 322 yards and three touchdowns vs. Arizona ... was 19-of-27 passing for 223 yards and two touchdowns in the first half ... 44 passing attempts to 12 different receivers matched a career high ... 300-yard passing game vs. Arizona was the eighth of his career - one short of third on Stanford’s all-time list
- Completed 18-of-29 for 245 yards and a touchdown at Colorado to become the ninth player in school history to eclipse 6,000 career passing yards ... also surpassed 6,000 career total yards in that game
As a Junior (2018)
- Team captain
- All-Pac-12 second team
- Pac-12 All-Academic honorable mention
- Started all 13 games
- Finished 269 of 413 passing (65.1%) for 3,540 yards and 29 touchdowns
- Second-most passing yards in a season in school history (3,540)
- Second-most 300-yard passing games in a season in school history (7)
- Third-most passing touchdowns in a season in school history (29)
- Third-most yards of total offense in a season in school history (3,520)
- Fourth-most completions in a season school history (269)
- Fifth-best passing efficiency in a season in school history (155.0)
- Led Pac-12 and 12th in nation with 8.57 yards per attempt
- Led Pac-12 and 16th in the nation with 155.0 passing efficiency
- Second in the Pac-12 and Top 25 in the nation in completion percentage (65.1%), completions per game (20.7), passing touchdowns (29), passing yards (3,540) and passing yards per game (272.3)
- Second in the Pac-12 with 270.8 yards of total offense per game
- 21 of 31 passing for 332 yards and four touchdowns in win over San Diego State (Aug. 31)
- 16 of 27 passing for 183 yards and a touchdown in win over USC (Sept. 8)
- 17 of 30 passing for 214 yards and two touchdowns in win over UC Davis (Sept. 15)
- 19 of 26 passing for 327 yards and three touchdowns, including 23-yard game-winner in overtime at No. 20 Oregon (Sept. 22)
- 15 of 27 passing for 174 yards and one touchdown at Notre Dame (Sept. 29)
- 26 of 41 passing for 381 yards and one touchdown vs. Utah (Oct. 6)
- 22 of 29 passing for 231 yards and one touchdown, and 18 rushing yards in win at Arizona State (Oct. 18)
- 34 of 43 passing for 323 yards and four touchdowns, and 19 rushing yards vs. Washington State (Oct. 27)
- Sixth-most completions in a game in school history, and most since 1994
- 29 of 43 passing for 347 yards and two touchdowns at Washington (Nov. 3)
- 23 of 33 passing for 342 yards and four touchdowns, and 45 yards rushing in win over Oregon State (Nov. 10)
- 23 of 37 passing for 344 yards and five touchdowns in win at UCLA (Nov. 24)
- Second-most passing touchdowns in a game in school history
- 18 of 29 passing for 237 yards and one touchdown in win at Cal (Dec. 1)
- 6 of 17 passing for 105 yards in Sun Bowl win over Pitt (Dec. 31)
As a Sophomore (2017)
- Pac-12 All-Academic honorable mention
- 11 games played
- Seven games started
- 124 of 211 passing for 1,573 yards, 14 touchdowns and four interceptions
- 28 rushes for 92 yards and three touchdowns
- 5 of 9 for 80 yards and 25-yard rushing touchdown in collegiate debut vs. Rice
- 13 of 19 passing for 123 yards, two passing touchdowns, 9-yard rushing touchdown vs. UCLA
- 15 of 24 passing for 173 yards and one touchdown in first career start vs. Arizona State
- 5 of 9 passing for 57 yards, and 19 rushing yards at Utah
- 5 of 6 passing for 59 yards and one touchdown vs. Oregon
- 9 of 20 passing for 105 yards and 14-yard touchdown run at Washington State
- 16 of 27 passing for 211 yards, and 26 rushing yards vs. Washington
- 17 of 26 passing for 185 yards and one touchdown, and 16 rushing yards vs. Cal
- 14 of 22 passing for 176 yards and four touchdowns vs. Notre Dame
- 10 of 22 passing for 192 yards and two touchdowns vs. USC (Pac-12 Championship Game)
- 15 of 27 passing for 212 yards and three touchdowns vs. TCU (Alamo Bowl)
As a Freshman (2016)
- Did not see action
Prior to Stanford
- Played at Santa Margarita Catholic (Calif.) under head coach Rick Curtis
- Varsity letters in football (4) and basketball (1)
- Five-star recruit by PrepStar
- Four-star recruit by Scout, Rivals, 247Sports and ESPN
- Nation's 13th-best recruit by PrepStar, 19th by ESPN
- Nation's second-best pro-style quarterback by Rivals, second-best pocket passer by ESPN
- California's second-best recruit by ESPN, third by PrepStar
- U.S. Army All-America
- Elite 11 finalist
- 2015 Trinity League MVP
- 2016 all-state
- 2015 all-state
- Holds 19 school records
- 8,222 career passing yards (broke Carson Palmer's school record)
- 62 passing touchdowns (school record)
- 19 rushing touchdowns
- 452 single-game passing yards (school record)
- Presidential Honor Roll (4.0 GPA or higher)
Personal
- Full name is Kevin Richard Costello
- Born in Newport Beach, Calif.
- Son of Kevin and Annette Costello
- Two siblings, Paige and Tiffany
- Enjoys ping pong and golf