But the anticipated backlash from the band's mostly female fans did not materialize and after the band broke up, Gately enjoyed some success as a solo artist.
His only solo album "New Beginning" made it to the U.K. Top 10 and produced three hit singles. He also starred in several musicals, including Andrew Lloyd Webber's "Joseph and the Amazing Technicolor Dreamcoat" in 2003-04.
He and Boyzone's other members reunited in February 2008, selling out two concert tours. The band also released two new singles, with the video for one of the songs, "Better," showing two men embracing in a montage of romantic couples.
The video aroused some controversy, with a Northern Ireland Presbyterian minister, the Rev. David McCullough, saying it was "yet another subtle effort of the homosexual propaganda machine."
"This video, that will be watched by millions, is sending out a deadly message to young people. It is stating that homosexuality is simply another norm," McCullough said.
Some public criticism notwithstanding, Gately appeared to have found peace in his private life. His Roman Catholic parents had accepted his homosexuality four years before his public admission, he told The Sun.
He underwent a "commitment ceremony" in Las Vegas with Cowles in 2003, and his most recent project was said to be a children's fantasy novel, "The Tree of Seasons."
His last message on Twitter, posted Oct. 6, alluded to the book, saying, "Still busy -- lots going on. Focusing on finishing my book next so may be quiet here."
Hundreds of fans posted messages on Gately's Facebook page, expressing their shock and sadness at his death.
Emily Louise Smith wrote, "As part of Boyzone, u were a big part of my life growing up [...] It hurts to know u are gone and the memories u and the lads shared will always be cherished."
Suzannah Summers posted a message saying, "RIP Stephen, it's such a shame to hear that you have left us at such an early age, i was so shocked wen i heard [sic]. you'll always be missed but forever in the hearts and minds of your fans."