Robert Downey Jr
Robert Downey Jr poses with two hogs on St Patrick's Day Twitter: @RobertDowneyJr

The world over, people celebrated St Patrick's Day on 17 March with a variety of festivities... from guzzling green beer to sporting clothes in the traditional colour. Hollywood was not far behind in the revelry, celebrating the Irish holiday with family.

Robert Downey Jr posed for a comic photo wearing a green onesie decorated with clover leaf print. Also in the photo were two hogs. "The three of us will be looking for you at the parade. Happy St Paddy's Day!" the Iron Man actor wrote alongside the post.

Fergie had her son Axl Jack pose for an adorable photo sporting green hair, tee and beaded necklaces. She was not the only celebrity to bring in the celebrations with the family. Mariah Carey, went the glitz way, wearing a green dress in a green car, with her kids Moroccan and Monroe popping poses alongside their mother.

Catherine Zeta Jones posted two photos to celebrate St Paddy's Day, one of a scene in County Cork and another of her grandmother.

"Celebrating my Irish roots today. Shout out to County Cork. Here with my Nanna. Kathleen O'Callagan (can't sound more Irish than that) she was always my lucky charm, now she's my guardian angel. Love you and miss you Nanna," she captioned the images.

Check out some of the other celebrities who celebrated the day with special posts on social media:

#Happystpatricksday #gogreen ☘☘🍀🍀 #RoseCrane @staronfox #greenday 🇮🇪

A post shared by Naomi Campbell (@iamnaomicampbell) on

#HappyStPatricksDay from me and my littlest leprechaun. ☘️🇮🇪

A post shared by Mark Wahlberg (@markwahlberg) on

Katie, aged 7, presents a lovely posy. Her dad is Colour Sergeant Darren Lorimer of The Irish Guards regiment. #StPatricksDay

A post shared by Kensington Palace (@kensingtonroyal) on

#flashbackfriday and #stpatricksday all in one #oldiebutagoodie

A post shared by Sarah Michelle (@sarahmgellar) on

Happy St. Patrick's Day 🍀🍀🍀 #demkids #stpatricksday

A post shared by Mariah Carey (@mariahcarey) on

Happy #stpatricksday ☘️

A post shared by Kerry Washington (@kerrywashington) on

Set your DVRs! @theellenshow and I are at it again tomorrow! #chiphappens

A post shared by kristen bell (@kristenanniebell) on

Happy St. Patrick's Day world!!!! 🍀🍀 #AxlJack

A post shared by Fergie (@fergie) on

Found the pot of gold!! ☘🌟🌈 Happy #StPatricksDay 💚 (👗: @draperjames)

A post shared by Reese Witherspoon (@reesewitherspoon) on