Kieran Tierney, born on 5 June 1997 (age 28), is a Scotland international from the Isle of Man and a left-back for Celtic, wearing squad number 63. He first made his name at Celtic without the usual loan detour, which said plenty about how quickly he was trusted and how little appetite there was for delaying the obvious.
His first Celtic spell brought serious substance: five Premiership titles, three Scottish Cups and two League Cups. He left in August 2019 for Arsenal for around £25m, a fee that reflected both his level at the time and the rarity of Celtic producing a full-back with that mix of aggression, delivery and durability.
Tierney returned to Celtic from Arsenal in July 2025. It was not a nostalgic cameo. In 2025-26 he has been a regular first-team presence, with strong and consistent form, and his league return of six goals in 32 appearances has made it his most productive league season.
Across the season he has made 49 Celtic appearances in all competitions, scoring six goals, including 32 in the league, four in the League Cup, two in the Scottish Cup, two in Champions League qualifying and nine in the Europa League. He has also remained involved with Scotland, making three World Cup qualifying appearances and scoring once.
His current market value is around £7m, according to Transfermarkt. Tierney’s career has taken him from Celtic to Arsenal and back again, but his importance in the 2025-26 side is not built on memory. He is playing, contributing, and still matters.
