With the transfer window set to close this week on Friday, August 30, Celtic have so far signed four players in the shape of Viljami Sinisalo, Kasper Schmeichel, Paulo Bernardo and Adam Idah.
Heading in the opposite direction is Matt O'Riley, the 23-year-old having now officially left the club for Brighton and Hove Albion after weeks of speculation.
O'Riley's departure follows the likes of Joe Hart (retired), Hyeon-gyu Oh (Genk), Sead Haksabanovic (Malmo), Benjamin Siegrist (Rapid Bucurest), and Hyeok-kyu Kwon (Hibs on loan), and goes down as the most lucrative outgoing in both Celtic's history and Scottish football history as a whole.
But where does O'Riley's sale to Brighton rank in the pantheon of outgoing Celts over the years? Read on for the Celtic top 10 most expensive transfer sales of all time.
10. Fraser Forster – £10m
Position: GoalkeeperSold to: Southampton Year sold: 2014Age when sold: 26
'La Gran Muralla' was the name the Spanish media gave Fraser Forster following two stellar Champions League performances against Barcelona back in 2012. After a season-long loan in 2010, Forster signed on a permanent basis at Parkhead the following year. He returned on another season-long loan in 2019, and accrued 236 appearances across both spells.
=10. Liel Abada – £10m
Position: MidfielderSold to: Charlotte FCYear sold: 2024Age when sold: 22
One of former Celtic manager Ange Postecoglou's first signings, Liel Abada played a key role in the Australian's double-winning and treble-winning seasons in Glasgow's east end. The Israeli featured less under current manager Brendan Rodgers during the Irishman's first season after returning to the club, before moving Stateside to play in the MLS. Abada featured 112 times for Celtic.
9. Jeremie Frimpong – £10.5m
Position: DefenderSold to: Bayer LeverkusenYear sold: 2021Age when sold: 20
Signed as a young project player, Jeremie Frimpong's talent was quickly identified by Neil Lennon, Damien Duff and John Kennedy. Shortly after moving north of the border, the winger deservedly found himself in the Celtic starting XI, and played an integral part of the club's success during the 2019/20 season. Frimpong made 51 appearances for Celtic across all competitions.
8. Virgil Van Dijk – £11.5m
Position: DefenderSold to: SouthamptonYear sold: 2015Age when sold: 24
As identified early doors by then club captain Scott Brown, Virgil Van Dijk took Scottish football in his stride. As comfortable on the front foot as he was on the back, the Dutchman dazzled during his time at Parkhead, earning a move to Southampton in 2015. A few years later, Van Dijk would lift the English Premier League and UEFA Champions League trophies at Liverpool – but not before racking up 115 appearances at Celtic.
7. Victor Wanyama – £12.5m
Position: MidfielderSold to: SouthamptonYear sold: 2013Age when sold: 22
One of Victor Wanyama's crowning moments at Celtic was his first-half header that broke the deadlock against Barcelona in the UEFA Champions League at Celtic Park in 2012.
Wanyama was a powerhouse in midfield and more than stood up to the physicality of Scottish football, while also turning on the style in Europe. At just 22 years of age, Wanyama left the Hoops for the Premier League, with 91 Celtic appearances to his name.
6. Kristopher Ajer – £13.5m
Position: DefenderSold to: BrentfordYear sold: 2021Age when sold: 23
Another young player who went from strength to strength, firstly under the guidance of Brendan Rodgers during the manager's first spell in the Celtic dugout, and then Neil Lennon during his second.
After being sent on loan to Kilmarnock, Ajer returned and quickly found himself in the Celtic starting XI. The Norwegian moved to Brentford in the summer of 2021, having featured 176 for the Parkhead side.
5. Odsonne Edouard – £14m
Position: ForwardSold to: Crystal PalaceYear sold: 2021Age when sold: 23
Odsonne Edouard left in the same window as Kris Ajer above, having helped Celtic secure the 'Double Treble' of 2017/18 while on loan from Paris Saint-Germain, and the 'Treble Treble' the following year having signed on a permanent basis. In four years at the club, Edouard made 179 appearances for the Hoops.
4. Moussa Dembele – £18m
Position: ForwardSold to: LyonYear sold: 2018Age when sold: 22
Moussa Dembele announced himself to the Paradise faithful when he netted a hat-trick against Rangers during what was his, and manager Brendan Rodgers', first taste of the derby.
Huge performances and goals to match followed, not least a double against Manchester City in the UEFA Champions League group-stage of the 2016/17 trail, and the cheekiest of Panenka penalties against the club's rivals at Hampden en route to the 'Double Treble'.
3. Kieran Tierney – £25m
Position: DefenderSold to: ArsenalYear sold: 2019Age when sold: 22 A product of the Celtic youth academy, Kieran Tierney broke into the Celtic first-team under manager Ronny Deila. An integral part of the club's sweeping success between 2016-2019, Tierney left the club for Arsena in the summer of 2019 for a then-record club and national fee.
Despite his age, he left having played 170 times for Celtic under three different managers.
2. Jota – £25m
Position: MidfielderSold to: Al Ittihad Year sold: 2023Age when sold: 24
Another of Ange Postecoglou's first signings – first on loan and then on a permanent basis from Benfica – Jota, like Abada noted above, was integral to Celtic's success during his time in Glasgow.
Known for his skill, pace and movement in the final third, Jota scored a catalogue of important goals under Postecoglou as he helped his side clinch a domestic double in 2022, and a treble in 2023 – making 83 appearances in green and white along the way.
1. Matt O'Riley – £25+m
Position: MidfielderSold to: Brighton and Hove AlbionYear sold: 2024Age when sold: 23 Signed in January 2022 under then manager Ange Postecoglou for just £1.5m from MK Dons, Matt O'Riley impressed in flashes during the early stages of his Celtic career.
Often vying for his place in the starting XI with Aaron Mooy, O'Riley stepped up during Brendan Rodgers' first post-return season – drawing the attention of everyone from Liverpool to Inter Milan, Atletico Madrid, Atalanta, and, indeed, Brighton and Hove Albion, who ultimately secured the 23-year-old's signature in the summer of 2024.
Exact details on the deal itself remain unclear, but it's understood O'Riley's move to the English Premier League sits between £25-30m, making him the most lucrative transfer sale in Celtic's history and Scottish football.
