Early life and youth football Kieran Tierney was born on 5 June 1997 in
Douglas on the
Isle of Man, and moved to
Wishaw in Scotland aged 10 months. He supported
Celtic as a child and signed for the club when he was seven years old. He was educated at
Motherwell schools St Brendan's RC Primary and
Our Lady's High (one year group behind fellow footballers, twins
Nicky and
Chris Cadden) then attended
St Ninian's High School, Kirkintilloch, which has a development partnership with Celtic. He has spoken of his hope of emulating the late
Tommy Gemmell, a member of the
Lisbon Lions team who also grew up in Wishaw (specifically,
Craigneuk) and played in the same position. He travelled with the first-team squad on a pre-season trip to Finland in August 2014, and made his debut in a friendly against
Tottenham Hotspur there. Although Celtic lost, Tierney described his first appearance for the first team as a "dream come true".
Celtic 2015–16: Debut and breakthrough Tierney made his competitive senior debut for Celtic on 22 April 2015, coming on as an 81st-minute substitute in a
Scottish Premiership match against
Dundee. He made one further first-team appearance that season, playing over an hour in a league match away at
St Johnstone. Tierney enjoyed a breakthrough season in
2015–16, appearing in over 30 matches and displacing the more experienced
Emilio Izaguirre as first-choice
left back. For his performances he was awarded with both the
Players' and
Writers' Young Player annual awards, After making his first appearances in the
group stage of the
UEFA Champions League, Tierney suffered ankle ligament damage during training on 27 October 2016 and was initially ruled out of action for two months. During the layoff, which caused him to miss the
League Cup final, he received treatment on a recurring shoulder injury and attended several Celtic matches as a typical supporter in the company of his childhood friends.
2017–2019: Back-to-back domestic trebles , Celtc v.
FC Salzburg, 2018 On 22 January 2017, after missing three months, he made his long-awaited return to the Celtic team in a
Scottish Cup tie against
Albion Rovers. Tierney was crowned PFA Scotland Young Player of the Year for the second consecutive season on 7 May, making him the first to achieve this since
Craig Levein in 1986. He suffered a jaw injury early in the
Scottish Cup final and had to be substituted for treatment. Celtic won the match 2–1 to complete a
domestic treble and
undefeated season. In spite of his lengthy injury absence, he featured in 40 matches during the campaign. On 8 August 2017, Tierney was named as
captain while also moving to
central defender to command a back line of teenagers in a
Scottish League Cup fixture against
Kilmarnock; Celtic won the game 5–0, with Tierney providing an
assist and scoring with a "wonderful strike" from 40 yards. On 30 October, a week after scoring in an important
league victory away to closest challengers
Aberdeen, he extended his contract with Celtic until 2023. By the end of the season, he had collected further personal accolades—winning both the
Players' and
Writers' Young Player awards for the third campaign in succession—and performed a major role in securing a historic 'double treble' for the club, making more than 50 appearances and playing the entirety of the domestic cup finals, both being 2–0 wins over
Motherwell. He then suffered from a hernia, which subsequently required surgery.
Arsenal 2019–2023: FA Cup win and injuries On 8 August 2019, Tierney signed for
Premier League club
Arsenal, for a reported £25 million fee. Tierney missed the early part of the 2019–20 season, having undergone a double hernia operation in May 2019. He made his first-team debut for Arsenal in a 5–0 win against
Nottingham Forest in the
EFL Cup on 24 September. Tierney assisted the first goal in a 4–0 home win against
Standard Liège scored by
Gabriel Martinelli a week later. He made his first appearance in the Premier League on 27 October, in a 2–2 draw with
Crystal Palace. His season was further disrupted after suffering a dislocated shoulder in the game against West Ham United. Tierney's impressive performances for Arsenal following the resumption of the Premier League after the
COVID-19 pandemic saw him receive Arsenal's Player of the Month award for June. He scored his first goal for Arsenal on 26 July, in a 3–2 win against
Watford on the final day of the 2019–20 Premier League season. On 1 August 2020, Tierney was selected to start in the
FA Cup final against Chelsea, as Arsenal won their 14th FA Cup. On 28 August 2020, Tierney was in the starting 11 in the
2020 FA Community Shield, which Arsenal clinched a 5–4 victory over
Liverpool in the penalty shootout after the match was 1–1 after 90 minutes. On 2 January 2021, Tierney scored the opening goal in a 4–0 away league win over
West Bromwich Albion and later assisted the final goal, scored by
Alexandre Lacazette. His stunning strike was subsequently voted the January Goal of the Month on the Arsenal official website. On 25 February, he scored a goal in a 3–2 win over
Benfica in the
Europa League round of 32, making him the first Scotsman to score for Arsenal in a European competition since
Willie Young in March 1980. In June 2021, he signed a long-term contract with Arsenal. Tierney played regularly for Arsenal during the 2021–22 season until suffering a season-ending knee injury in March. Arsenal lost league games against
Crystal Palace,
Brighton,
Tottenham and
Newcastle following his injury, and they narrowly missed out on Champions League qualification. This led to speculation that Tierney would look to leave Arsenal during the summer of 2023.
2023–2024: Loan to Real Sociedad On 27 August 2023, Tierney joined
La Liga club
Real Sociedad on a season-long
loan. He made his full debut in a 5–3 win over
Granada, for which he was labelled 'exquisite' by Real Sociedad boss
Imanol Alguacil. He followed this up with an impressive performance against
Real Madrid on 17 September. His season was interrupted by two hamstring injuries, sustained in September and January.
Return from loan Tierney returned to Arsenal over the summer after picking up a hamstring injury at
Euro 2024. He made his long-awaited return to training on 21 November 2024. On 20 April 2025, he made his 100th
Premier League appearance for the club, in a 4–0 win over
Ipswich Town at
Portman Road. On 25 May 2025, Tierney opened the scoring in a 2–1 win away to
Southampton in his final game for the club, having made a total of 144 appearances in all competitions, scoring 6 goals.
Return to Celtic Tierney's former club,
Celtic, confirmed in February 2025 that they had reached a pre-contract agreement for him to return to the club on a permanent basis in the summer of that year. His departure from Arsenal was announced in June 2025, and he signed a five-year contract with Celtic later that month. On 3 August, he made his second debut for the club in a 1–0 win against
St Mirren in the league. He scored the first goal of his second spell on 9 November; the second in Celtic's 4–0 win against
Kilmarnock. On 1 March 2026, Tierney scored Celtic's first goal against their
arch rivals Rangers, as the
Hoops came from 2–0 down to draw 2–2 in the Scottish Premiership game at
Ibrox. ==International career==