Brighton defender Shane Duffy has joined Celtic on a season-long loan.
The Republic of Ireland international makes the move to Parkhead, subject to international clearance, after amassing 130 appearances in four years on the south coast.
Celtic are expected to pay a loan fee of just under £2m and will contribute to a large chunk of his £45,000-per-week wages, which is believed to be in the region of £25,000.
- Celtic face EL trip to Latvia or San Marino
- Ajeti on target again as Celtic cruise past Motherwell
- Transfer Centre LIVE!
Sky Sports News reported on Monday that Celtic had made a loan bid for the centre-back, with West Brom and West Ham also keen on signing him this summer.
Duffy became Brighton's record signing in 2016 when he joined on a £4.7m deal from Blackburn, and helped the Seagulls secure promotion to the Premier League in his first season.
The 28-year-old has been called up for international duty with Ireland as Stephen Kenny's side prepare to face Bulgaria and Finland in the Nations League.
"I really am delighted to sign this deal with Celtic," Duffy told the club's website. "It is a huge honour for me to join Celtic, such a huge institution and a brilliant football club that I have always loved and admired.
"It will be a fantastic personal moment for me when I pull on the Celtic jersey. It's just a great feeling - I could not be happier to be part of the club now."
Celtic are bidding for a 10th straight title in Scotland - and they bounced back from last week's Champions League defeat with a 3-0 victory over Motherwell on Sunday.
"It's a huge season. I don't need a reason to go to Celtic but if there ever was one it's this season and the chance to make history," Duffy said in an interview on the FAI's Twitter.
"To have the chance to be a part in it is a huge honour, but there is a lot of hard work to do to get that 10 in a row.
"I know the fans are optimistic and I am as well. We'll do the hard work and hopefully the reward is there at the end."
'A leader and warrior'
Celtic manager Neil Lennon added: "We are delighted to bring a player of Shane's quality to Celtic.
"He is leader and he's a warrior - someone with real ability and who will also give us that great physical presence. I know too he is a player who will add great personality to the dressing room. This is a real coup for the club.
"From the off, Shane wanted to come to Celtic and we are delighted we have been able to fend off English Premier League interest."
Transfer Centre LIVE!
All the latest news, analysis and rumours from the window in one place.
The summer transfer window will run for 10 weeks from July 27 and close at 11pm on October 5.
A domestic-only window for trades between the Premier League and EFL then runs from October 5 and closes on Friday, October 16 at 5pm. Follow all the news and analysis on Sky Sports News and across Sky Sports' digital platforms, including with our dedicated Transfer Centre blog.