On May 24, 2019, Biggio was called up to the Toronto Blue Jays.[22] He made his major league debut that night versus the San Diego Padres, striking out twice and grounding out in his three at-bats.[23] Two days later, on May 26, he got his first major league hit off Robbie Erlin of the Padres.[24] In his next at bat that game, he hit his first home run off Matt Wisler.[25] On September 17, Biggio hit for the cycle against the Baltimore Orioles at Oriole Park at Camden Yards,[26] becoming the third player in Blue Jays history to accomplish the feat, following Jeff Frye in 2001 and Kelly Gruber in 1989. Biggio had four RBI, scored three runs, and stole two bases in the game.[27] Cavan, alongside his father, Craig (who hit for the cycle for the Houston Astros on April 8, 2002), joined Gary Ward and his son Daryle as only the second father and son duo to hit for the cycle in MLB history.[28] On the season, Biggio hit .235/.364/.429 with 16 home runs, 48 RBI, and 14 stolen bases in 100 games.[29]
Overall, during the COVID-19 pandemic shortened 2020 season, Biggio batted .250/.375/.432 with eight home runs and 28 RBI in 59 games.[30] In 2021 with the Blue Jays, he batted .224/.322/.356 with seven home runs and 27 RBI in 79 games.[29] In Triple–A, Biggio batted .182 with three home runs and 11 RBI across 22 games.[16] On March 22, 2022, he signed a $2.123 million contract with the Blue Jays, avoiding salary arbitration.[31] He played in 97 games for the Blue Jays and slashed .202/.318/.350 with six home runs and 24 RBI.[29]
On January 13, 2023, Biggio signed a one-year, $2.8 million contract with the Blue Jays, again avoiding salary arbitration.[32] In 111 games for Toronto, he slashed .235/.340/.370 with nine home runs and 40 RBI.[33]
Biggio played in 44 games for Toronto in 2024, hitting .200/.323/.291 with two home runs, nine RBI, and two stolen bases.[29] On June 7, 2024, he was designated for assignment.[34]
Los Angeles Dodgers
On June 12, 2024, the Blue Jays traded Biggio and cash considerations to the Los Angeles Dodgers in exchange for minor league pitcher Braydon Fisher.[35] He played in 30 games for the Dodgers, batting .192 with three home runs and 10 RBI.[29] Biggio was designated for assignment by the Dodgers on August 5[36] and was released on August 8.
San Francisco Giants
On August 23, 2024, Biggio signed a minor league contract with the San Francisco Giants.[37] He played in 12 games for the Triple–A Sacramento River Cats, slashing .163/.413/.326 with two home runs, six RBI, and two stolen bases.[16]
Atlanta Braves
On September 7, 2024, Biggio was traded to the Atlanta Braves in exchange for cash considerations.[38] He played in one game for the Triple–A Gwinnett Stripers before he was added to the major league roster on September 11.[39] In 4 games for Atlanta, Biggio went 1–for–5 (.200). On November 1, Biggio was removed from the 40–man roster and sent outright to Gwinnett, but rejected the assignment in favor of free agency.[40]
Kansas City Royals
On January 5, 2025, Biggio signed a minor league contract with the Kansas City Royals.[41]
Personal life
Cavan's brother Conor also played baseball for St. Thomas and Notre Dame,[42] and was a 34th round draft selection by the Houston Astros in the 2015 MLB draft. Conor later went to work for the Office of the Commissioner of Baseball.[43] As of the 2020–21 collegiate season, his sister Quinn played softball for Notre Dame.[44]
Upon reaching the major leagues, Biggio and Vladimir Guerrero Jr., who had been called up a month earlier, became the first teammates in MLB history to be sons of Hall of Fame players.[45]