Joshua Jackson says Reese Witherspoon and Kerry Washington helped him prepare for fatherhood.

Joshua Jackson

Joshua Jackson

The 'Little Fires Everywhere' star praised the "supermoms" for helping him get ready to become a dad to his baby girl.

Asked who was the most supportive co-star on the set of the Amazon Prime series, he told The Hollywood Reporter: "I was going through a pretty significant change during the show: I found out my wife was pregnant. So having a collection of supermoms around me helped with everything from finding doctors to baby clothes to 'what to expect' advice."

Joshua thanked his partner Jodie Turner-Smith for being a great parent and wife as they celebrated Mother's Day last month.

He wrote on Instagram: "Dear Jodie, On this most special of mothers days, I want to thank you for the being the light that you are. For the the passion with which you threw yourself into nurturing and protecting our child when she was in your womb.

"For the dedication and will you showed bringing her into the world. 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. 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. I love seeing you enter the pantheon of mothers. And I look forward to walking this path by your side as we nurture this little engine of joy you have blessed the world with."