[6] After the 2014 season Buehler played for Team USA[7] and the Yarmouth–Dennis Red Sox of the Cape Cod Baseball League (CCBL).

[9] In the 2014 CCBL playoffs, he did not allow a run in 15+1⁄3 innings, won both of his starts, and was a co-winner of MVP honors,[10] leading the Red Sox to the league championship.

[15] He finally made his professional baseball debut on August 23, 2016, for the Arizona League Dodgers, striking out three and retiring all six batters he faced.

[19] While with the Drillers, he made 11 starts with a 3.49 ERA and was selected to appear in the mid-season Texas League all-star game.

[20] He was promoted to the Triple-A Oklahoma City Dodgers at mid-season[21] where he made three starts before transitioning to the bullpen in preparation for a potential September major league callup.

[28] Buehler made his first major league start on April 23, 2018, against the Miami Marlins, pitching five scoreless innings.

At the same time he became only the third pitcher in MLB history (after Dwight Gooden and Pedro Martínez) with multiple games with 15 strikeouts and no walks in the same season.

[41] Buehler finished the 2019 regular season with a record of 14–4, and a 3.26 ERA (9th in the NL) in 30 starts, with two complete games and 215 strikeouts.

[28] In the NLCS against the Atlanta Braves, he started the first and sixth games, working a total of 11 innings with only one run allowed while striking out 13.

[44] In the third game of the 2020 World Series, Buehler picked up the win against the Tampa Bay Rays, striking out 10 in six innings while allowing one earned run on three hits.

He was the third-youngest pitcher with 10 or more strikeouts and three or fewer hits in a World Series game, behind only Ed Walsh in 1906 and Josh Beckett in 2003.

[57] On April 25, he pitched his first career shutout against the Arizona Diamondbacks, striking out 10 batters and allowing only three hits and no walks.

However, after one two-inning minor league rehab appearance the team announced that he would not return in 2023 and hoped to be back for the start of the 2024 season.

After a rough outing on June 18 in which he surrendered seven earned runs in four innings to the Colorado Rockies, Buehler returned to the injured list with a hip injury.

[69][70] Concerned about his performance, Buehler left the team to work out by himself at a private sports facility in Florida[71] before rejoining Oklahoma City for another rehab stint, with mixed results.

[72] The Dodgers activated him on August 14 for his first major league start in almost two months, and he again struggled, leading him to say that he was not meeting his standard of performance.

[77] On December 28, 2024, Buehler signed a one-year deal with the Boston Red Sox for $21.05 million guaranteed, plus incentives.

[78] Buehler has heard the famous roll call scene from the 1986 film Ferris Bueller's Day Off many times throughout his life.

[79] Buehler embraced the nickname "Ferris," incorporating it into his Twitter handle and wearing it on his jersey during the 2018 MLB Players Weekend.

He has a minority ownership stake in 2020 Kentucky Derby and 2020 Breeders' Cup Classic winner Authentic, trained by Bob Baffert.

Buehler is married to McKenzie Marcinek, whom he began dating in high school, and the couple reside in Lexington.