The case originally saw the senior pastor of a wealthy Singaporean Christian church handed an eight year jail term.
The case, which involved raunchy music videos featuring celebrities like rapper Wyclef Jean alongside the wife of City Harvest Church's leader Kong Hee, originally saw the senior pastor handed an eight year jail term.
But Singapore's High Court halved the 52-year-old's 2015 sentence for misusing around Sg$50 million ($35.6 million) in church funds in the failed attempt to turn his wife Sun Ho, also a pastor, into a global pop star.
The case was described by state prosecutors as the largest misappropriation of charity funds in the city-state's legal history.
Prosecutors had argued that Kong should be jailed for up to 12 years, but a three-judge appeals court Friday sentenced him to three years and six months in jail.
Five other leaders at the glitzy megachurch, which used pop music to attract members and boost donations, also saw their original prison sentences reduced by the court ruling.
Appeals court judge Chao Hick Tin said the church leaders "were acting in what they genuinely believed to be in CHC’s interests."
Ho, 44, was never charged with any crime and did not attend the hearing.
The courtroom was packed, mostly with supporters. Kong, who sat stoically throughout the hearing, was "disappointed" at the outcome, his lawyer Edwin Tong said.
"He will be mulling over the judgement... then decide what happens (next)," he said.
A district court convicted the six church leaders of fraud for diverting Sg$24 million from the church building fund to help Ho, a Mandarin pop singer, break into the global English-language market.
They were also found guilty of misappropriating another Sg$26 million to cover their tracks with a complex web of sham financial transactions.
Kong and his wife were once a high-profile power couple in Singapore who led the expansion of their congregation, which had more than 30,000 members at its peak several years ago.
The pop-music venture, dubbed the "Crossover" project, was aimed at attracting "the unchurched" across the world, particularly young people, through Ho's music.
Ho moved to Los Angeles in 2009 where she starred in several racy videos, including "China Wine", which featured Wyclef Jean and was widely viewed -- and ridiculed -- on YouTube.
In another video for a reggae-tinged song entitled "Mr Bill", Ho appeared as an Asian wife who sings about killing her African-American husband, played by supermodel Tyson Beckford.
But her showbiz ambitions were scuttled by the financial scandal, which saw the church investigated by the city-state's white collar crime unit.
Tiny Singapore is one of the world's most affluent nations. Despite being a largely Buddhist and Taoist society, the city-state is home to well-funded Christian groups.