He attended Mission Viejo High School, where he was a multi-sport athlete and became a notable baseball prospect with selections to all-county and all-league teams.

Patrick Sandoval was born on October 18, 1996, in Mission Viejo, California, to Jorge,[1] originally from Mexico City,[2] and Robin.

[8] He gained further media attention on April 30 for throwing a two-hit shutout against Capistrano Valley High School to aid Mission Viejo in its CIF Southern Section (CIF-SS) playoff hunt and improve his season stats to a 6–2 record with a 2.38 ERA.

[7] He threw another shutout on May 13, blanking Trabuco Hills High School and receiving praise from his coach for inducing an increased amount of whiffs.

[10][11] On August 10, Sandoval partook in the Perfect Game All-American Classic at Petco Park in San Diego, pitching 2⁄3 of an inning and recording a strikeout.

[12] In November 2014, his senior year in high school, Sandoval signed his National Letter of Intent to play college baseball for Vanderbilt University.

In his first professional game on August 1, 2015, he pitched two innings while giving up eight hits and five runs (four earned) and striking out three against the GCL Phillies.

[23] Sandoval began the 2018 season with Quad Cities and compiled a 7–1 record in 14 games (10 starts) with a 2.49 ERA, 71 strikeouts, and a save across 65 innings.

[21][22] In 26 games (20 starts) between Quad Cities, Buies Creek, Inland Empire, and Mobile, he was 11–1 with a 2.06 ERA, striking out 145 batters in 122+1⁄3 innings pitched.

[29][30] He made his major league debut that night versus the Cincinnati Reds, pitching five innings behind opener Taylor Cole while allowing two runs and striking out eight.

He made his first start of the year on July 28 against the Seattle Mariners, pitching four innings while giving up an earned run and striking out four.

[32] On August 28, Sandoval was optioned to the Angels' alternate training site that was being used in place of the cancelled 2020 minor league season.

On September 23, Sandoval was credited with his first career win after throwing three shutout innings against the San Diego Padres at Petco Park.

Sandoval received another start on the final day of the season, throwing 2+2⁄3 innings against the Los Angeles Dodgers while giving up two runs and striking out three.

[32] Sandoval began the 2021 season as a reliever but was added to the starting rotation in late May when José Quintana was placed on the injured list.

[34] On July 24, 2021, in a start against the Minnesota Twins at Target Field, Sandoval carried a no-hit bid into the ninth inning before giving up a double to Brent Rooker with one out.

[35] On August 27, Sandoval was placed on the 60-day injured list due to a lower back stress fracture, officially ending his season.

Angels general manager Perry Minasian praised Sandoval's season, calling it an "outstanding year" and "something to build off of".

[40] On August 19, 2022, in a game against the Detroit Tigers at Comerica Park, Sandoval threw the first ever shutout of his career, allowing four hits and no walks with nine strikeouts.

He accomplished the feat with 97 pitches, making it the first Maddux for the Angels since Ricky Nolasco did so in 2016 and the first in MLB since Ranger Suárez on September 25, 2021.

[44] By September 12, Sandoval led the majors with 19 unearned runs allowed;[45] however, his fielding-independent pitching (FIP) average of 4.19 at the end of the season was higher than his ERA.

[55] During a game against the United States national baseball team on March 12, Sandoval started and pitched three innings while giving up two hits, a run, and striking out two.

[56] Sandoval started for Mexico during a semifinal game against the Japan national baseball team on March 20 and pitched 4+1⁄3 innings while giving up four hits and no runs, striking out six, and receiving a no decision.

Sandoval threw his 93 mile per hour (150 km/h) fastball nearly half the time in his first two major league seasons but decreased its usage in 2021, a change that was accompanied by an improved ERA.