Kieran Tierney, born on 5 June 1997 in Scotland, is a 28-year-old defender renowned for his role as a left back at Celtic. He dons the number 63 shirt and stands at 1.78m (5ft 10in) with a weight of 76kg (11st 13lb). He has also represented the Scotland national team. His current market value approximates around €8.00m (£7m), according to Transfermarkt.
In July 2005, a young Tierney joined Celtic in the Scottish Premiership as a trainee. His time at Celtic was marked by consistent growth and an increasing presence on the field. In his debut season of 2014 - 2015, he made two first team appearances in league matches. His appearances increased each season with 23 first team appearances and one goal in 2015 - 2016, 24 appearances and one goal in 2016 - 2017, and a remarkable 32 appearances and three goals in the 2017 - 2018 season. In the 2018 - 2019 season, he made 21 first team appearances, capstoning his stint at Celtic.
In a rather momentous decision, Tierney transferred from Celtic to Arsenal in the English Premier League in August 2019 for a reported fee of around £25m. His performances at Arsenal seemed to mirror his time at Celtic, with steady increases in appearance and involvement on the pitch. Between 2019 and 2023, he made many appearances and scored several goals before being loaned out.
In August 2023, Tierney embarked on a brief stint in Spain with Real Sociedad in the LaLiga, on loan from Arsenal. The season at Sociedad saw him making 20 first team appearances. In July 2024, upon completion of his loan, Tierney returned to Arsenal where he continued to make his presence felt on the field until July 2025.
In July 2025, Tierney made the monumental decision to return to Celtic, his original club where he had spent his formative years as a player. His performance and consistency from his earlier years seemed to have followed him back home as he made 16 first team appearances and scored three goals in the current season of 2025 - 2026.
Tierney’s portfolio also includes several international and club tournament appearances, such as the Champions League Qualifiers 2025 - 2026 for Celtic and the Euro Qualifiers 2022 - 2024 for Scotland, making significant contributions to his team's performances.
