Troyal Garth Brooks was born on February 7, 1962, in Tulsa, Oklahoma. He was the youngest child of Troyal Raymond Brooks, Jr. (1931–2010), a draftsman for an oil company, and Colleen McElroy Carroll (1929–1999), a 1950s-era country singer of Irish ancestry who recorded on the Capitol Records label and appeared on Ozark Jubilee. This was the second marriage for each of his parents, giving Brooks four older half-siblings (Jim, Jerry, Mike, and Betsy). The couple had two children together, Kelly and Garth. At their home in Yukon, Oklahoma, the family hosted weekly talent nights. All of the children were required to participate, either by singing or doing skits. Brooks learned to play both the guitar and banjo.

While Brooks' musical style placed him squarely within the boundaries of country music, he was strongly influenced by the 1970s singer-songwriter movement, especially the works of James Taylor, whom he idolized and named his first child after, as well as Dan Fogelberg. Similarly, Brooks was influenced by 1970s-era rock of Billy Joel, and Bruce Springsteen and the operatic rock of Queen with Freddie Mercury.

As a child, Brooks often sang in Casual family settings, but his primary focus was athletics. In high school, he played football and baseball and ran track and field. He received a track scholarship to Oklahoma State University in Stillwater, where he competed in the javelin. Brooks graduated in 1984 with a degree in advertising. His roommate, Ty England, later played guitar in his road band until going solo in 1995.

In 1985, entertainment attorney Rod Phelps drove from Dallas to Listen to Brooks. Phelps liked what he heard and offered to produce Brooks' first demo. With Phelps' encouragement, including a list of Phelps' contacts in Nashville and some of his credit cards, Brooks traveled to Nashville to pursue a recording contract; he returned to Oklahoma within 24 hours. Phelps continued to urge Brooks to return to Nashville, which he did. In 1987, Brooks and wife Sandy Mahl moved to Nashville, and Brooks began making contacts in the music industry.

Brooks married his college sweetheart, Songwriter Sandy Mahl, on May 24, 1986. The couple later had three daughters: Taylor Mayne Pearl (born 1992), August Anna (born 1994), and Allie Colleen Brooks (born 1996) Brooks and Mahl separated in March 1999, announcing their plans to divorce on October 9, 2000, and filing for divorce on November 6, 2000. The divorce became final on December 17, 2001. Brooks remarried on December 10, 2005, to country singer Trisha Yearwood. In July 2013, Brooks became a grandfather when August had daughter Karalynn with Chance Michael Russell.

Garth Brooks' eponymous first album was released in 1989 and was a chart success. It peaked at No. 2 on the Billboard Top Country Albums chart, and reached No. 13 on the Billboard 200 chart. Most of the album was traditionalist country, influenced in part by George Strait. The first single, "Much Too Young (To Feel This Damn Old)", was a country top 10 success. It was followed by Brooks' first number-one single on the Hot Country Songs chart, "If Tomorrow Never Comes". "Not Counting You" reached No. 2, and "The Dance" reached No. 1; its music video, directed by John Lloyd Miller, gave Brooks his first push towards a broader audience. Brooks has later claimed that out of all the songs he has recorded, "The Dance" remains his favorite. In 1989, Brooks embarked on his first major concert tour, as opening act for Kenny Rogers.

Following the release of Fresh Horses, Brooks embarked on his second world tour. Its total attendance, approximately 5.5 million, ranks third on the all-time list of concert attendance, and its gross of over $105 million ranks it among the highest-grossing concert tours in the 1990s.

Brooks' third album, Ropin' the Wind, was released in September 1991. It had advance orders of 4 million copies and entered the Billboard 200 at No. 1, a first for a country Artist. The album's musical content was a melange of pop country and honky tonk; singles included "The River", "What She's Doing Now", and a cover of Billy Joel's "Shameless". It would become Brooks' second-best selling album, after No Fences. The success of Ropin' the Wind further propelled the sales of Brooks' first two albums, enabling Brooks to become the first country Artist with three albums listed in the Billboard 200's top 20 in one week.

Brooks released his first Christmas album, "Beyond the Season" on August 25, 1992. The album included classics such as "White Christmas" and "Silent Night" as well as an original tune "The Old Man's Back in Town." "Beyond the Season" was the best selling Christmas album in 1992, peaking at No. 2 on the Billboard 200 chart.

Brooks' first world tour began in 1993, reaching the UK after many domestic concerts. Brooks sold out venues such as Birmingham's National Exhibition Centre and London's Wembley Arena, a feat never accomplished by an American country music Artist. He also began the London radio station, Country 1035. Despite the disdain of the British media, Brooks' overall popularity in the country was evident, with a top disc jockey, Nick Barraclough, referring to Brooks as Garth Vader (a play on Darth Vader) for his "invasion" of the charts and his success in the country genre. Unlike Alan Jackson, who refused to return to the UK after being treated in a similar negative manner by the press, Brooks would later return in 1996 for more performances. Brooks also took is World Tour to other regions throughout Europe, as well as Brazil, the Far East, Australia, and New Zealand.

In 1994, Brooks paid homage to one of his musical influences, Kiss, appearing on the tribute compilation, Kiss My Ass: Classic Kiss Regrooved, a collection of songs performed by popular artists from various genres. The unlikely collaboration of Brooks and Kiss' rendition of "Hard Luck Woman" was performed live on The Tonight Show with Jay Leno, and despite its hard-rock appeal, Brooks' version appeared on the Billboard Hot Country Songs chart.

In November 1995, Brooks released Fresh Horses, his first album of new material in two years. Within six months of its release, the album had sold over three million copies. Despite its promising start, Fresh Horses plateaued quickly, topping out at quadruple platinum. The album's lead single, "She's Every Woman" peaked at No. 1 on the Billboard Hot Country Songs chart; however, its follow-up single, "The Fever" (an Aerosmith cover) only peaked at No. 23, becoming Brooks' first country single to not chart on the top 10. However, Brooks had three additional top 10 singles from the album, including "The Beaches of Cheyenne", which reached No. 1.

In 1997, Brooks released his seventh studio album, Sevens. The album was originally scheduled to be released in August 1997, allowing for promotion during Brooks' Central Park concert; however, plans went awry after a dispute within Capitol Records. The Central Park concert went on as planned, receiving 980,000 fans in attendance and becoming the largest concert in park history.

In 1998, Brooks launched his Touch 'em All Foundation with Major League Baseball. He also began with a short career in baseball, when he signed with the San Diego Padres for spring training in 1998 and 1999. Brooks' performance on the field did not warrant management placing him on the regular season roster; however, he was offered a non-roster spot, but declined it. The following season, Brooks signed with the New York Mets. This spring-training stint was also a poor performance for Brooks, resulting in a zero-for-seventeen batting record.

In a 1999 interview with George, Brooks said, "[...]But if you're in love, you've got to follow your heart and trust that God will explain to us why we sometimes fall in love with people of the same sex." Lyrics to his song, "We Shall Be Free", features the line, "When we're free to love anyone we choose," which has been interpreted as a reference to gay relationships. Brooks won a 1993 GLAAD Media Award for the song.

In 2000, Brooks appeared at the Equality Rocks benefit concert for gay rights. He sang a duet with openly gay singer George Michael.

Brooks' final album before retirement, Scarecrow, was released on November 13, 2001. The album did not match the sales levels of Brooks' heyday, but still sold well, reaching No. 1 on Billboard 200 and Top Country Albums charts. Although he staged a few performances for promotional purposes, Brooks stated that he would be retired from recording and performing at least until his youngest daughter finished high school.

In 2004, Brooks returned to baseball with the Kansas City Royals. He got his first and only hit off Mike Myers during his final spring training game with the Royals.

In 2005, Brooks ended his association with Capitol Records and established his own record label, Pearl Records. Brooks has released four compilation albums via Pearl Records, as well as his 2014 studio album (also released through RCA Records Nashville).

In early 2006, Walmart reissued The Lost Sessions as a single CD apart from the box set, with additional songs, including a duet with Trisha Yearwood, "Love Will Always Win", which reached the top 25 on the Billboard Hot Country Songs chart. The couple were later nominated for a "Best Country Collaboration With Vocals" Grammy Award.

The RIAA has since reexamined their methods for counting certifications. Under their revised methods, Presley became the best-selling solo Artist in U.S. history, making Brooks the number-two solo Artist, ranking third overall, as the Beatles have sold more albums than either he or Presley. The revision brought more criticism of the accuracy of the RIAA's figures, this time from Brooks' followers. On November 5, 2007, Brooks was again named the best selling solo Artist in US history, surpassing Presley after audited sales of 123 million were announced. In December 2010, several more of Presley's albums received certifications from the RIAA. As a result, Elvis again surpassed Brooks. As of October 2014, the RIAA lists Presley's total sales at 134.5 million and Brooks' at 134 million. Subsequently, Man Against Machine has been certified by the RIAA as Platinum and listing Brooks sales as exceeding 136 million, placing Brooks again as the #1 selling solo Artist.

Brooks is also a fundraiser for various other charities, including a number of children's charities and famine relief. With wife Trisha Yearwood, Brooks sang Creedence Clearwater Revival's "Who'll Stop the Rain" on the Shelter from the Storm: A Concert for the Gulf Coast nationwide telethon for Hurricane Katrina relief. He performed the Garth Brooks: Live in LA benefit concerts, five sold out concerts over two days at the Staples Center in Los Angeles, California on January 25 and 26, 2008 (setting numerous records at the high-profile venue in the process). These concerts were staged to raise money for Fire Intervention Relief Effort, serving those impacted by the 2007 California wildfires. Tickets were priced at $40 each and all five shows (totaling more than 85,000 tickets) sold out in 58 minutes. CBS broadcast the first concert live as a telethon for additional fundraising.

On October 15, 2009, Brooks suspended his retirement to begin Garth at Wynn, a series of periodic weekend residency shows at Encore Las Vegas on the Las Vegas Strip. The schedule allowed Brooks both to have the family life during the week and to continue to perform on the weekend. The financial terms of the agreement were not announced, but Steve Wynn did disclose that he gave Brooks access to a private jet to quickly transport him between Las Vegas and his home in Oklahoma.

Brooks, along with wife Yearwood, has supported Habitat for Humanity's work over the years, including the annual Jimmy & Rosalynn Carter Work Project. They have worked alongside the Carters in the United States and in Haiti, lending their time and voices to help build safe, decent and affordable homes. Brooks' Teammates for Kids Foundation provided more than $1 million in funding to Habitat to help build homes in Thailand following the Asian tsunami. In December 2010, Brooks played nine shows in less than a week in Nashville at Bridgestone Arena to benefit victims from the May 2010 Nashville flood. Over 140,000 tickets were sold and $5 million raised.

Brooks graduated from Oklahoma State University–Stillwater where he starred on the track team. He later completed his MBA from Oklahoma State and participated in the commencement ceremony on May 6, 2011.

In 2012, Brooks officially passed the Beatles as the top-selling act of the past 20 years, moving 68.5 million units worldwide, almost 5 million more than the Beatles. In May 2014, Brooks' total album sales reached 69,544,000 copies, which makes him the best-selling album Artist in the U.S., ahead of the Beatles (65,730,000), Metallica (54,365,000), Mariah Carey (54,280,000) and Celine Dion (52,234,000).

Brooks' half-sister Betsy Smittle, who died in 2013, was a well-known musician - releasing her own album Rough Around the Edges as Betsy - and part of Brooks' band for some years; she also worked with the late country star Gus Hardin and other Musicians in Tulsa. Smittle was also a lesbian, and Brooks has credited her with some of the inspiration for his support for same-sex marriage.

In 2014 Brooks was awarded the Arkansas Traveler certificate by State Senator, Jason Rapert.

In September 2015, it was announced Brooks would reissue his album No Fences later in the year to commemorate its 25-year release anniversary. The release would include a new version of "Friends in Low Places", featuring George Strait, Jason Aldean, Florida Georgia Line, and Keith Urban singing along with Brooks. The album release has since been delayed due to royalty disputes. The track was later featured on his 2016 compilation album, The Ultimate Collection.

In September 2016, Brooks became the first and only Artist in music history to now achieve seven career Diamond Award albums, according to the RIAA.