Scottish defender Jamie Walker has become Dundalk's fourth signing of the winter transfer window.
The 22-year-old full-back joins from Scottish League One outfit Kelty Hearts and is moving to Oriel Park on a permanent deal.
His arrival follows the signings of winger Robbie Mahon, Dutch midfielder Koen Oosterbrink and ex-UCD player Dara Keane.
"Jamie is a player we have been tracking," Dundalk head coach Stephen O'Donnell said.
"He has a cultured left foot, defends well, is a good athlete and he can handle the ball so he will suit our style of play.
"He hasn’t played for the last few weeks so he will be fresh and we feel he has a lot of scope to improve, both from a physical and from a playing point of view, and we are looking forward to working with him."
Walker said he was relishing the challenge of playing in the SSE Airtricity Men's Premier Division.
"It's a great opportunity for me," he said.
"The chance to come to a good league and play against, and with, good players was something I wanted to do and I feel I can really improve here under the gaffer.
"I know that there are some very good players in the League of Ireland so it’s a good challenge for me to go and prove myself in a new environment and I’m looking forward to it.
"I’m an attacking full-back and I like defending in one-on-one situations. I love playing football and can’t wait to get out and play in front of the Dundalk fans."
Dundalk will open their 2024 campaign with a trip to reigning four-in-a-row champions Shamrock Rovers on Friday, 16 February at Tallaght Stadium.
Celtic have signed winger Nicolas Kuhn from Rapid Vienna for an undisclosed fee.
The 24-year-old has signed a five-and-a-half-year deal at Parkhead.
Manager Brendan Rodgers told the club's website: "We are delighted to welcome Nicolas to Celtic. We believe he is a dynamic player who has an excellent level of quality and all the attributes to fit well into our style of play.
"He has a real attacking intent, a player with great pace and ideas, the ability to create and score goals and a player with a great energy and work ethic.
"He is someone who can play wide on both sides so he brings with him that versatility for us too."
Kuhn added: "I'm really excited and I can't wait to play out here. It's unbelievable and I don't really have words. This is what every footballer dreams of.
"I can play on the left, as a second striker or as a number 10. Most of the time, though, I have played on the right wing.
"I am really motivated to do well for this great club and I want to get working immediately as we face our challenges in the league and the cup this year, so I'm really excited for what's coming."
Additional reporting: PA
