A new survey by ComRes found over 1.2 million adults are tuning into Premier Christian Radio regularly, with 951,000 people listening to Premier Praise and 765,000 listening to Premier Gospel every week.
Premier CEO Peter Kerridge believes he knows why.
"In a digital age when you can manage your finances, shop, book holidays, and do a myriad of other things, all with your mobile phone I'm not surprised by these figures," he said.
"It's obvious that people are searching for a spiritual experience outside of traditional church gatherings and in an on-demand world this trend will accelerate. Whatever device people choose to engage with Premier, phone, radio, or online the experience is the same.
"Christian Radio is intimate and private, it touches the soul. Listeners therefore are intentional as they listen to hear Christian messages amplified by great communicators."
While recent statistics have shown a decline among young people attending church, for the first time ever, people aged 18 - 35 made the largest proportion of listeners on all three of Premier's radio stations.
Justin Brierley, presenter of Premier Christian Radio's award winning programme Unbelievable?, said a desire for "answers to the big questions of life" is another reason more millennials are listening to Premier's stations.
"Young people may not be showing up in our churches but it's clear that the spiritual hunger experienced by all human beings hasn't disappeared," he added.
Charmaine Noble-McLean, head of content for Premier, highlighted the importance of connecting with an younger audience.
"Both Premier Gospel and Premier Praise are intentionally aimed at younger listeners," she said.
"We talk about the issues that young people want to hear about, and we talk about them from a Christian perspective. I think that's why millennials are choosing to listen and we are delighted that the younger audience appears to be crossing over to Premier Christian Radio which isn't typically aimed at a younger generation."
Figures have shown a steady decline in church attendance since 2013, when numbers fell below a million for the first time ever.
Those regularly attending a Sunday service in the Church of England dipped below three quarters of a million last year, despite a commitment from the General Synod to address the falling numbers.
Mr Kerridge said Premier's latest listening stats demonstrate it's time for the Church to make changes to get more people worshiping God.
He explained: "The Church could learn from Facebook, it could learn from radio, it could learn from how the newspapers are reinventing themselves.
"The Church has to go on the journey and it has to find ways to break out of their buildings and into people's lives."
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