The radio and TV presenter admitted that when she had started the podcast four years ago, she had been "texting people that I knew or kind of knew" to see whether they would agree to be interviewed, and told Metro that she had struck gold with Dawn French.
She said: "I remember texting Dawn French, and she went, ‘What’s a podcast?’ And I was like, ‘Oh, s***. I’m just gonna chat to you.’ And she was like, ‘only if you come to Cornwall’.
"I have to thank Dawn really for a lot, because she really took a chance on letting me try out this… I was experimenting on those first few episodes, I didn’t know what I was doing.
That then gave way for other people to go, ‘oh, wow, if Dawn went on it and was talking about divorce, and adoption, and all sorts of, you know, very complex issues, maybe it’s alright to do that’. So Dawn really helped in terms of that."
Happy Place has seen Cotton, 40, interview a huge number of stars including Miriam Margolyes, David Harewood, Ruth Wilson, Anne-Marie and Suranne Jones.
She said that one of the interviews that had affected her most was with Ashley Cain, who lost his baby daughter Azaylia to leukaemia last April at just eight months old.
Describing herself as "in awe of" Cain, she said "it felt like he needed to...not hold all of the pain in anymore" and said she felt "honoured" to have heard him talk so openly.
Cotton recently admitted that she didn't do live radio shows any more because she suffered from panic attacks over them.
She told the Daily Star: "I would not sleep the night before, I'd have a panic attack before.
"I'd probably be fine when I'm on air, it's just the bit before that I can't get myself through with ease."
Watch: Fearne Cotton says depression made her feel ashamed