Zito became engaged to former Miss Missouri Amber Seyer in April 2011, and they were married on December 3, 2011.
His father, Joe Zito, who died June 19, 2013, at the age of 84, composed and arranged music for Nat King Cole in the early 1960s (ca.1961–64) and arranged for the Buffalo Symphony Orchestra.
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 is also a musician.
He plays guitar, and he co-wrote the song "Butterflies" that was used in the Eddie Murphy film A Thousand Words.
Zito's uncle is television actor Patrick Duffy, who was married to his maternal aunt.

Zito and wife Amber gave birth to their first child, a son named Mars, in July 2014.
They adopted their second child, a  son named Mercer Joseph Zito, in May 2017.
A third child, a son named Rome, was born February 2020
Zito is known for his idiosyncrasies and his offbeat personality.
Early in his career, Zito dyed his hair blue.
He earned the nicknames "Planet Zito" and "Captain Quirk" when with Oakland.
Zito says he likes the way his uniform number 75 looks because the 7 and the 5 are like a "shelf" to hold the name "Zito" up.
He surfs and practices yoga.
He has done yoga poses in the outfield, and meditated before games.
Zito practices Transcendental Meditation and supports the David Lynch Foundation.
Zito has said, however, that he believes terms such as "flaky" or "hippie" have been applied to him by people who do not know him well enough to know better.

Zito was raised in a "spiritual, metaphysical type church" that was founded by his grandmother and that his mother, Roberta, who died in 2008, formerly preached at.
In 2001, Zito espoused a universal life force that he credited with his midseason turnaround.
He said that he discovered this force by reading Creative Mind by Ernest Holmes.

However, in August 2011, Zito became a Christian, saying he "committed to Jesus Christ as his Lord and Savior."
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.
He got a tattoo (his only one) of a golden calf on the inside of his right bicep as a reminder for him to "not worship false idols" and to remember that God comes first.
Zito said that his wife is a Christian as well.
In 2019, Zito wrote Curveball: How I Discovered True Fulfillment After Chasing Fortune and Fame (ISBN 0785227881), a memoir book about his life and his conversion to Christianity.
Zito has said, “Having placed my full identity into my baseball career for most of my life, only to have it stripped away during the 2010 World Series run is what led me to discover my true identity.
Not in a game, but in Jesus Christ.”

Zito founded the charity Strikeouts For Troops.
The charity provides comforts of home and works to lift the spirits and morale of injured US troops and offers support to military families.
In 2010, Zito announced that he would donate $1,500 for every strikeout in the Giants–Padres game on September 11.
There were a total of 14 strikeouts in the game.

In 2003, Zito portrayed a United States Navy petty officer in an episode of JAG on CBS.
Zito's character, a pitcher, faced assault charges after hitting a Marine with a ball during the annual Navy-Marine all-star baseball game.
Zito became engaged to former Miss Missouri Amber Seyer in April 2011, and they were married on December 3, 2011. His father, Joe Zito, who died June 19, 2013, at the age of 84, composed and arranged music for Nat King Cole in the early 1960s (ca.1961–64) and arranged for the Buffalo Symphony Orchestra. 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 is also a musician. He plays guitar, and he co-wrote the song "Butterflies" that was used in the Eddie Murphy film A Thousand Words. Zito's uncle is television actor Patrick Duffy, who was married to his maternal aunt.
Zito and wife Amber gave birth to their first child, a son named Mars, in July 2014. They adopted their second child, a  son named Mercer Joseph Zito, in May 2017. A third child, a son named Rome, was born February 2020
Zito is known for his idiosyncrasies and his offbeat personality. Early in his career, Zito dyed his hair blue. He earned the nicknames "Planet Zito" and "Captain Quirk" when with Oakland. Zito says he likes the way his uniform number 75 looks because the 7 and the 5 are like a "shelf" to hold the name "Zito" up. He surfs and practices yoga. He has done yoga poses in the outfield, and meditated before games. Zito practices Transcendental Meditation and supports the David Lynch Foundation. Zito has said, however, that he believes terms such as "flaky" or "hippie" have been applied to him by people who do not know him well enough to know better.
Zito was raised in a "spiritual, metaphysical type church" that was founded by his grandmother and that his mother, Roberta, who died in 2008, formerly preached at. In 2001, Zito espoused a universal life force that he credited with his midseason turnaround. He said that he discovered this force by reading Creative Mind by Ernest Holmes.
However, in August 2011, Zito became a Christian, saying he "committed to Jesus Christ as his Lord and Savior." 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. He got a tattoo (his only one) of a golden calf on the inside of his right bicep as a reminder for him to "not worship false idols" and to remember that God comes first. Zito said that his wife is a Christian as well. In 2019, Zito wrote Curveball: How I Discovered True Fulfillment After Chasing Fortune and Fame (ISBN 0785227881), a memoir book about his life and his conversion to Christianity. Zito has said, “Having placed my full identity into my baseball career for most of my life, only to have it stripped away during the 2010 World Series run is what led me to discover my true identity. Not in a game, but in Jesus Christ.”
Zito founded the charity Strikeouts For Troops. The charity provides comforts of home and works to lift the spirits and morale of injured US troops and offers support to military families. In 2010, Zito announced that he would donate $1,500 for every strikeout in the Giants–Padres game on September 11. There were a total of 14 strikeouts in the game.
In 2003, Zito portrayed a United States Navy petty officer in an episode of JAG on CBS. Zito's character, a pitcher, faced assault charges after hitting a Marine with a ball during the annual Navy-Marine all-star baseball game.
Barry Zito