Gallagher was born on 2 March 1948 to Daniel and Monica Gallagher at the Rock Hospital in Ballyshannon, County Donegal, Ireland. He was baptised in the nearby St Joseph’s Church.

His father, Danny, originally from Derry, had served for a period in the Irish Army. He was also an accordionist and led his own dance orchestra. He met Gallagher’s mother, Monica—who was from County Cork—during the 1940s while stationed in Cork city, and the two later married.

The couple moved to Ballyshannon after Danny was demobilised, where he found work with the Irish Electricity Supply Board, which was then constructing the Cathaleen’s Fall hydroelectric power station on the River Erne.

In 1949, the family relocated to Derry City, where Gallagher’s younger brother, Dónal, was born later that year. Dónal would eventually go on to manage Gallagher throughout most of his career. While in Derry, Gallagher attended the Christian Brothers Primary School, known locally as “the Brow of the Hill”.

Over the next seven years, the family moved frequently due to irregular employment, spending periods in Coventry and Birmingham in England, as well as oscillating between Cork and Derry. The instability strained Danny and Monica’s marriage, and in 1956 Monica returned to Cork permanently with her two sons. They lived with Gallagher’s maternal grandparents in an apartment above the Modern Bar (later renamed Roche’s Bar) at 27 MacCurtain Street. Gallagher attended the North Monastery School and later St Kieran’s College.

Gallagher developed a passion for music at a young age through radio broadcasts, tuning in to Radio Luxembourg, the BBC, and the American Forces Network. His earliest musical inspiration was Roy Rogers, “the Singing Cowboy,” followed by Lonnie Donegan, whose skiffle interpretations of American blues and folk artists introduced Gallagher to the genre. He later discovered rock and roll—particularly Buddy Holly, Eddie Cochran, and Chuck Berry—before finding his most significant influence in Muddy Waters. He also cited Woody Guthrie, Big Bill Broonzy, and Lead Belly among his inspirations.

At the age of nine, Gallagher received a plastic Elvis Presley–style ukulele for Christmas, on which he taught himself basic chords. Recognising his talent, his mother later bought him an acoustic guitar. Gallagher studied music books from the local library, such as Lonnie Donegan’s Skiffle Hits, and copied chord shapes from musician photographs in Melody Maker.

After building a repertoire of songs, Gallagher began performing at small local events around Cork, often accompanied by his brother. In 1961, he won a cash prize as a solo performer in a talent competition at Cork City Hall, and his photograph appeared in the Evening Echo.

As Gallagher’s performances became more frequent, he sought to emulate the electric sound of contemporary beat groups. To achieve this, he persuaded his mother to buy him a black Rosetti Solid Seven electric guitar.

1966–1968: Taste I

After returning to Ireland, Gallagher jammed with the local Cork band the Axills, which included bassist Eric Kitteringham and drummer Norman Damery. He was offered the role of guitarist, but after completing his musical apprenticeship in the showbands—and inspired by the rise of beat groups—he decided it was time to form his own band. He invited Kitteringham and Damery to join him.

They formed The Taste, later shortened to Taste, a blues-rock and R&B power trio. The band was conceived inside the Long Valley Bar, and the name Taste was inspired by a beermat advertising the superior taste of Beamish stout.

Taste began rehearsing upstairs at 5 Park View, where the Kitteringham family lived, and made their debut on 10 September 1966 at a school dance in the Imperial Hotel on Cork’s Grand Parade. While the band played many covers, they were also developing original material, including an early version of “Blister on the Moon.”

Hoping to tap into Belfast’s growing blues scene, Taste played Sammy Houston’s Jazz Club on Great Victoria Street in December 1966. Their performance attracted the attention of promoter Eddie Kennedy, who offered them both a residency at the Maritime Hotel and a management contract.

Gallagher persuaded Kitteringham and Damery—then working as a printer and an insurance broker—to become full-time musicians, and they agreed. Several months later, Damery’s work replacement died in the Aer Lingus Flight 712 disaster, prompting Damery to tell Gallagher: “Whatever turns out for me professionally now is a bonus. You saved my life.”

During their Maritime Hotel residency, Taste opened for acts like Cream, Fleetwood Mac, and Chris Farlowe & The Thunderbirds, drawing mixed Protestant and Catholic audiences.

In 1967, Phil Solomon’s Major-Minor label invited Taste to record a demo. Without Gallagher’s consent, the label released “Blister on the Moon” (with “Born on the Wrong Side of Time” as the B-side) as a single.

Through Eddie Kennedy’s connections with Robert Stigwood—manager of Cream and the Bee Gees—Taste secured shows at London’s Marquee Club. At their debut performance in February 1968, supporting Robert Hirst and the Big Taste, they were billed as “The Erection” to avoid confusion with the headliner. Their raw sound immediately impressed critics and audiences, earning them a residency and prompting a permanent move to London in summer 1968.

Polydor began expressing interest in signing the band, but Kennedy claimed the label wanted a stronger rhythm section. Despite Gallagher’s initial resistance, Kitteringham and Damery were ultimately replaced by Belfast musicians Richard McCracken (bass) and John Wilson (drums), both formerly of the band Cheese. The split was amicable, as all parties felt the change was necessary for the band’s progression.

1968–1970: Taste II

In August 1968, the new Taste lineup signed with Polydor and relocated to Earl’s Court. Gallagher bought a saxophone during this time and taught himself to play it, practicing in a cupboard to avoid disturbing neighbours.

Three months later, at Eric Clapton’s request, Taste supported Cream at its farewell concerts at the Royal Albert Hall. After Cream dissolved, manager Robert Stigwood approached Gallagher with an offer to join Jack Bruce and Ginger Baker in a new version of the band. Gallagher refused outright.

In early 1969, Taste recorded their debut album Taste in a single day at De Lane Lea Studios in London. Produced by Tony Colton—who had worked with Yes—the record featured rearranged blues standards such as “Leavin’ Blues,” “Sugar Mama,” and “Catfish,” a cover of Hank Snow’s “I’m Movin’ On,” and Gallagher’s original “Blister on the Moon.” Critics praised its “raw and honest” sound, and the album performed especially well in Northern Europe.

In July 1969, Clapton invited Taste to support his new supergroup Blind Faith on their U.S. tour. Despite strong audience response, the tour proved difficult: Taste were denied soundchecks, proper PA support, and were limited to daytime arena slots. Conflicts arose with Kennedy over travel arrangements and his refusal to let the band remain in the U.S. afterward to play club shows. While in New York, Gallagher saw Muddy Waters perform for the first time at Ungano’s.

After returning to London, Polydor asked Taste to begin work on a second album. This time they were given nearly a week in the studio. The result, On the Boards, showcased Gallagher’s progressive blues style—combining blues-rock, acoustic ballads, and experimental jazz-blues fusion. Released in January 1970, it reached No. 18 on the UK Albums Chart. Without Gallagher’s approval, Polydor issued its opening track, “What’s Going On,” as a single in Germany, where it became a Top 5 hit.

Throughout 1970, Taste grew rapidly as a live attraction, breaking the Marquee Club’s all-time box-office record on 21 July, surpassing Jimi Hendrix’s previous record. John Lennon, after attending one of their shows, told New Musical Express: “I heard Taste for the first time the other day and that bloke is going places.”

Behind the scenes, however, tensions were rising. Gallagher and his brother Dónal were aware that Kennedy was misappropriating band funds, but Wilson and McCracken sided with the manager, causing a deep rift. Matters worsened when Taste’s van was broken into the night before their Isle of Wight Festival appearance, and Wilson accused Gallagher of staging the theft because only his drum pedals were stolen.

Despite internal conflict, Taste delivered a powerful performance at the Isle of Wight Festival before an audience of roughly 600,000, returning for multiple encores. The entire performance was filmed by Murray Lerner and eventually released as Live at the Isle of Wight (2015).

Gallagher had intended to dissolve the band after the festival, believing Taste had “come to the end of our natural life.” However, contractual obligations forced them to continue. Three days later, they performed at the Montreux Jazz Festival—Gallagher’s first of many appearances there.

Taste played their final concert on 24 October 1970 at Queen’s University, Belfast. Afterward, Gallagher never again performed a released Taste song on stage. McCracken and Wilson later formed the rock band Stud.

Although Gallagher described the breakup as “traumatic” and “dreadful,” especially since “the press all attacked me as if I was some kind of dictator,” he refused to speak negatively about the other members. He later reflected that the split was a “communications breakdown” that “shouldn’t have been allowed to happen.”

Meanwhile, Dónal, now acting as Gallagher’s manager, insisted they take Eddie Kennedy to court to reclaim unpaid royalties. Kennedy capitulated before trial, agreeing to transfer the rights but claiming he had no money. Gallagher therefore never received income from Taste’s album sales. The ordeal made him deeply cautious of large management deals in the future.