Ireland and Irish people around the world celebrated the feast of their country's patron saint St Patrick on 17 March with gusto... and celebrities were not far behind. They shared their own celebrations of St Patrick's Day — from sporting green costumes to enjoying large glasses of Guinness to keeping it healthy with green tea popcorn.

One Directioner Niall Horan shared a photograph on Instagram and Twitter enjoying a glass of stout along with the message: "Happy St. Patrick's day everyone. Always proud of our little nation."

Happy St. Patrick's day everyone . . Always proud of our little nation .

A photo posted by Niall horan (@niallhoran) on

David Beckham, too, enjoyed a glass of Guinness and decided to share an image of it online.

Happy St Patrick's day 🍀🍀🍀🍀 @robbiekeane

A photo posted by David Beckham (@davidbeckham) on

Neil Patrick Harris celebrated the holiday with his twins Harper and Gideon, who were all set with their funky green sunglasses and accessories. "Happy St. Patrick's Day from NPH, David, and these two leprechauns," he captioned the image.

Happy St. Patrick's Day from NPH, David, and these two leprechauns. (Photo by @dbelicious) #blarney

A photo posted by Neil Patrick Harris (@nph) on

"It's not just about luck. When you work hard and follow your #BFOGs, anything is possible. Happy #StPatricksDay, everyone!" Tyra Banks posted, along with a picture from one of her photoshoots.

Rose McGowan uploaded a flashback image from her time working on the TV show Charmed alongside co-star Alyssa Milano. "Leprechauns made me wear the ugliest pants ever," she wrote on Instagram.

Leprechauns made me wear the ugliest pants ever. #leprechauns #eire #🍀 #irish

A photo posted by Rose McGowan (@rosemcgowan) on

Ryan Reynolds continued with his Deadpool jokes, this time around targeting Clark Kent aka Superman. "Happy St. Paddy's day from our pal," he captioned the meme.

Happy St. Paddy's day from our pal @mutant101

A photo posted by Ryan Reynolds (@vancityreynolds) on

He also posted a message on Twitter saying: "I adore the St. Patrick's Day tradition of fighting your whole family on the front lawn after sundown."

Carrie Underwood used the day to remind people to think before they ink, referencing her clover tattoo.

Jessica Alba had a healthy St Patrick's Day (yep, that's possible) with Matcha green tea popcorn.

Mariah Carey used Paddy's Day to show off her curves in an emerald green gown.

Kourtney Kardashian posted an image of her with sister Kim, both donning green glitter hats and shamrock necklaces.

TBT: Happy St. Patrick's Day! 🍀on my app. #LinkInBio

A photo posted by Kourtney Kardashian (@kourtneykardash) on

Michelle Monaghan also shared a pic of herself in a green hat and tee on Instagram.

Happy #stpatricksday!! #OOTD ☘ #irishgirl

A photo posted by Michelle Monaghan (@realmonaghan) on