Jim was one of the most versatile athletes ever to play in San Mateo County. He is the only athlete in Serra's history to letter in four varsity sports. As a football player. he was an All-CAL and All-County running back; he started as guard on the basketball team and in track, he anchored the league's winning relay team and set a record in the long jump that still stands! But it was on the baseball field that Jim really excelled, earning back-to-back all-league honors. leading the Padres to the 1959 CAL Championship.

After graduation. Jim signed with the Boston Red Sox and then went to the Angels in the expansion draft.

Jim's major league career spanned 18 seasons with four teams. He earned all-star honors 4 times during a career that saw him gain more than 1700 hlts. Jim later managed the Angels and White Sox, leading the Angels to their first Western Division title in 1982.

Fregosi returned in 1991 with the Phillies, hired again by former Angels teammate and General Manager Lee Thomas. His greatest triumph as a manager came in 1993, when he managed the club to the World Series. After finishing 26 games out of first place in 1992, the 1993 Phillies (featuring a cast of colorful characters including Darren Daulton, Lenny Dykstra, Dave Hollins, John Kruk, Danny Jackson, Curt Schilling, and Mitch Williams) charged to 97 wins and then further shocked the baseball world by pulling off a major upset against the two-time defending NL Champion Atlanta Braves in six games in the League Championship Series. Despite putting up a good fight against the defending World Champion Toronto Blue Jays in the World Series, Fregosi's Phillies wound up losing to Toronto in six games, with Joe Carter's Series-winning home run in Game 6 being the final blow.

Despite the World Series run, Fregosi was often the target of criticism by the Philadelphia sports media. One general criticism of Fregosi was that he was a manager who relied on veteran players and was unable to develop younger players. He was ultimately fired by the Phillies in 1996 after posting a series of dismal post-1993 seasons. Fregosi finished with a record of 431 wins and 463 losses in the regular season and six wins and six losses in the postseason.

Fregosi was hired away from the San Francisco Giants, where he had been serving as a special assistant, to become the new manager for the Blue Jays in 1999 one month before the season began. He replaced Tim Johnson, who was fired after one year due to lying about his military service. The team finished in third place and above .500 in each of Fregosi's two seasons in Toronto. On July 27, 2000, he won his 1,000th game as manager, doing so against the Seattle Mariners 7-2. Despite fair results, he was let go after the season. Fregosi finished with a record of 167 wins and 157 losses in the regular season. This ended up being his final managerial position in Major League Baseball. This was the only team where he finished with an overall winning record.

As a manager, he had a record of 1028 wins and 1094 losses in 15 seasons. He also managed 16 post-season games. His post-season record was seven wins and nine losses. At the end of 2004, when the Phillies were looking for a manager to replace Larry Bowa, Fregosi surfaced as a candidate for the job. The job ended up going to Charlie Manuel.

Fregosi's number 11 was retired by the Angels in 1998. Fregosi delivered a eulogy at the March 2007 funeral of longtime friend and former Phillies coach John Vukovich.

In February 2014, Fregosi was a part of an MLB Alumni cruise when he suffered multiple strokes. The cruise docked in the Cayman Islands where he was rushed to a local hospital, where his condition was stabilized by doctors before he was relocated to Miami. However, on February 13, Fregosi's condition declined and he died the following day. Phillies owner David Montgomery called Fregosi a "dear friend" after his death.