The Open started on Thursday, returning to Northern Ireland for the first time since 1951.
Here's everything you need to know about golf's oldest championship.
There are four major tournaments in golf, and The Open - the only one played outside of America - takes place around the UK.
The event is held over four days in the summer and is played at a different course each year.
This year's Championship matches at The Open will take place from Thursday 18 July 2019 and run until Sunday 21 July 2019.
The prize is one of sport's most famous trophies - a silver Claret Jug.
The Open is being played at Royal Portrush in Northern Ireland.
The small seaside town of Portrush is home to Royal Portrush Golf Club and three prominent golfers.
Golfer Rory McIlroy played on the course as a teenager, Graeme McDowell grew up in the town and Darren Clarke lives in Portrush.
For many people, the return of The Open to Portrush - 68 years after its one and only staging of golf's oldest championship - is a big moment for Northern Ireland.
Here are a few of the players to watch out for:
Rory McIlroy finished as a runner-up by two shots in 2018 and has won four majors already. He says lifting the Claret Jug on home soil on Sunday could see him "burst out crying".
Francesco Molinari defending Open champion Molinari will be hoping for another triumph following victory at The Open in Carnoustie, Scotland.
15-time major champion and three-time Open winner, Tiger Woods will be playing competitively in Northern Ireland for the first time. He won his 15th major in April, after having back surgery in 2017.
World number one and a four-time major champion Brooks Koepka may be American but he has some local knowledge of the course thanks to his caddie Portrush local Ricky Elliott.