He said he was now in a relationship with a man and has reconciled his Christianity and sexual orientation.
"I sit on the tailgate of my pickup truck, and I meditate, and I talk to God," he told celebrity magazine People.
Soon after the article appeared, another major name in country music said he was inspired by Herndon to come out -- Billy Gilman, who first entered the country charts in 2000 at age 11.
Compared with Herndon's choreographed coming out, Gilman's was rawly personal. He released an emotional video on YouTube, saying he was "scared to death" to go public but had been hurt by gossip about his life.
"Being a gay male country artist is not the best thing," Gilman said of the Nashville-based industry.
"If people don't like your music, that's one thing. But after having sold over five million records, having a wonderful life in the music industry, I knew something was wrong when no major label wanted to sit down and have a meeting and listen to the new stuff," he said.
The former child star said he was not ashamed to be gay but voiced dismay that he was "in a genre and in an industry that is ashamed of me for being me."
- More gay themes -
Openly gay artists have historically faced obstacles across genres. Pop giants such as Elton John and George Michael waited until well after they made it big before being public about their sexuality.
Boy George, when his band Culture Club was topping pop charts in the 1980s and his androgynous look faced scrutiny, famously told an interviewer that he preferred a "cup of tea" to sex.
The political and cultural climate has shifted rapidly in recent years, with same-sex couples now able to marry in 35 of the 50 US states -- most recently, through a court decision, in conservative and country music-loving South Carolina.
Country music is not uniform and Dolly Parton, one of biggest names in Nashville, has an avid gay following that she has embraced.
Two female country stars, Chely Wright and k.d. lang, are both out of the closet, although they have pursued careers out of the Nashville mainstream.
The winner for Song of the Year at this year's Country Music Association awards was Kacey Musgraves' "Follow Your Arrow," whose message of not caring about outsiders' judgment alludes both to same-sex love and marijuana-smoking.
"Do you guys realize what this means for country music?" Musgraves said as she accepted the award. She co-wrote the song with Brandy Clark and Shane McAnally, who are both openly gay but whose lyrics tend to stay gender-neutral.
The country industry's struggles with gay acceptance have also featured prominently on the television soap opera "Nashville," in which one of the main characters is gay, but remains in the closet and even marries a rising female star as he tries to maintain his heartthrob image with women.
- Insular world of Nashville -
Besides country music, hip hop -- whose stars often vie in their macho bravado -- also has relatively few openly gay stars. But Frank Ocean came out in 2012, and received words of support from the genre's titans such as Jay Z.
Gilman said that he has received encouragement from fellow country stars. But it remains to be seen how far Nashville will go.
Country music's popularity has grown rapidly in recent years, with country stars repeatedly topping the mainstream Billboard charts.
But country decision-makers are close-knit and see their key audience as 30- 35-year-old women, said Joseph Brant, managing digital editor of Out & About Nashville, a monthly newspaper aimed at the LGBT community.
"It's not like the industry is anti-gay. They are just trying to guess what they know about their core audience -- that there will be a disconnect, that these women, even if they are suburban moms, they still won't find that relatability," Brant said.
And while Herndon and Gilman are both big names, both already established themselves as stars years ago.
"If you had your number one this week and you come out this week, that's what's going to blow up the whole machine," said Brant.