The poll of nearly 500 full or part-time pastors, and youth, women and children's workers, also found that on average, they were working double the number of hours they were meant to.
On top of the third who had experienced burnout, another quarter of respondents said they were close to experiencing complete exhaustion and stress a number of times, before Christians leaders, friends and families helped them.
15% of respondents also reported working over 70 hours a week - an amount of hours known to increase risks to physical and mental health.
Why they said they were experiencing burnout:
Lack of time
Expectation to do too many things outside their skillset
Difficult relationships with congregations
Disagreements within leadership teams
Speaking on Premier's News Hour, Tim Thornborough, from the Good Book Company which ran the survey, explained what burnout means.
He said: "They cease to be able to function and that shows itself in all kinds of ways; struggling to sleep, depression, listlessness. You just feel unable to go on.
"We need friends, proper Sabbath rests [and] we need sleep. God has made us to sleep. We need inward renewal.
"Most of all, we need to just recognise who we are, that God has made us as fragile vessels. We start to imagine that we are super hereos who are able to bear and shoulder every burden. It's simply not true."
You can hear Tim Thornborough speaking with Premier's Hannah Tooley by clicking below:
