The actor welcomed his first child, a daughter, with wife Jodie Turner-Smith earlier this year, and the 42-year-old told The Hollywood Reporter his famous pals proved invaluable when it came to navigating parenthood.
"I was going through a pretty significant change during the show: I found out my wife was pregnant," Josh shared, as he named the two stars were the most supportive.
"So having a collection of super-mums around me helped with everything from finding doctors to baby clothes to 'what to expect' advice."
Earlier this year, the former "Dawson's Creek" star posted a letter on Instagram, in which he gushed about Jodie as she celebrated her first Mother's Day as a mum.
"I have never witnessed a more powerful being than you through those moments. Thank you for the depth of grace you have found since our daughter has arrived," he gushed.
"The commitment that you make look so effortless but I know is anything but. Thank you for making me a father. For trusting me enough to embark on this journey together. I am humbled more and more every day by that. I love you."