The same October, Zito helped lead the Giants to their second World Series title in San Francisco history over the Detroit Tigers by going 2–0 with a 1.69 ERA in three postseason starts.

[2] His parents were a show-business couple working for singer and pianist Nat King Cole and he had two sisters who were 9 and 13 years older than Barry.

His family moved to San Diego, California, to help him concentrate on his baseball career after he showed signs of promise from a very young age.

Not knowing much about baseball, his father began reading books about pitching strategy and even stopped working to help coach his son.

[4] In his sophomore season, Zito transferred to Los Angeles Pierce College so that he could be eligible for the Major League Baseball draft.

"[21] On September 8, Zito became the first pitcher in the AL to win 20 games when he pitched seven innings and allowed no earned runs against the Minnesota Twins.

In Game 1 of the ALDS, he allowed one run and four hits over eight innings, outdueling Johan Santana and earning the win in a 3–2 victory over the Twins and setting the stage for an Oakland sweep.

[46] Zito was a focal point of the 2006 trade deadline, and was widely rumored to be headed to the Mets in a potential deal for prospect Lastings Milledge.

Susan Slusser of the San Francisco Chronicle wrote that if the Mets were unwilling to trade Milledge, the Athletics might be interested in Aaron Heilman and John Maine.

[49] In his first start as a member of the Giants, Opening Day (April 3), Zito went five innings and allowed two earned runs against the San Diego Padres.

[50] Zito would earn his first win as a member of the Giants in his next start on April 16 when he went six innings, gave up three hits, and allowed no runs to the Colorado Rockies.

[53] Zito made his first Major League relief appearance on August 5 against the Padres due to an early exit by starter Noah Lowry and an overworked bullpen.

His 17 losses led the National League and were the second-worst total in San Francisco history (Ray Sadecki lost 18 games in 1968).

[4] In a rotation featuring Tim Lincecum, Matt Cain, Jonathan Sánchez, and Madison Bumgarner, Zito was the odd man out for the playoffs.

Zito worked out throughout the playoffs so that he would be ready to join the roster in case of an injury, but he was never needed and remained on the secondary squad.

[4] His replacement, Ryan Vogelsong, excelled, but Zito was able to rejoin the rotation when he returned in June because Sánchez was placed on the disabled list with left biceps tendinitis.

[4] After struggling mightily during spring training in which he threw with a new crouched delivery, Zito began the 2012 season with a start against the Rockies on April 9.

[76] In a June 3 home game matchup with the Cubs, Zito pitched four-hit shutout ball into the ninth inning for a 2–0 Giants win and brought his season ERA below 3.00.

[78] Zito had a hand in the Giants' second road shutout win of the season when he pitched seven innings, allowing three hits and recording four strikeouts, in a July 17 game versus the Atlanta Braves.

[4] Zito faced off against the Reds in Game 4 of the National League Division Series (NLDS) on October 10 and struggled, being pulled in the third inning after allowing two runs.

[83] That same day, Zito inspired the Twitter hashtag #rallyzito, which, behind the efforts of Giants fans, was trending worldwide on the social networking site.

As the Game 1 starter, Zito earned the win, outpitching Detroit's Justin Verlander by tossing 5+2⁄3 innings of one-run ball.

[90] However, Zito struggled for the rest of the season, going 2–10 with a 6.24 ERA after April 21 and losing his rotation spot a couple times late in the year.

[91][92] On September 25, manager Bruce Bochy decided to give Zito one final start with the Giants as a tribute to his tenure with the team.

[102] However, following a season-ending injury to Jesse Chavez, Oakland purchased Zito's contract from Triple-A on September 16, placing him on the major league roster.

Both pitchers received lengthy standing ovations from the sold-out Coliseum crowd (which included the third Big Three member, Mulder) upon leaving the game.

[124][125] Zito's mother Roberta was a musician who sang in a choral group known as The Merry Young Souls and with Nat King Cole and his band.

Zito explained that God got his attention through his being left off the 2010 Giants postseason roster and a car accident and freak foot injury in early 2011.

[136][138] In 2019, Zito wrote Curveball: How I Discovered True Fulfillment After Chasing Fortune and Fame, a memoir book about his life and his conversion to Christianity.

Zito's character, a pitcher, faced assault charges after hitting a Marine with a ball during the annual Navy-Marine all-star baseball game.