2010–11 Aberdeen F.C. season
The 2010-11 season was Aberdeen's 98th season in the top flight of Scottish football and their 100th season overall. Aberdeen competed in the Scottish Premier League, Scottish Cup and Scottish League Cup.
Aberdeen began the season with successive league wins over Hamilton Academical and St Johnstone, but suffered a poor run of form in the following months, culminating in a club record 0–9 defeat to Celtic in November 2010. The following month, Mark McGhee was sacked as manager and replaced by Motherwell manager Craig Brown.
In the cups, Aberdeen reached the semi-final of the Scottish League Cup, losing 1–4 to Celtic in January 2011. Aberdeen also reached the semi-final of the Scottish Cup, losing 0–4 to Celtic in April 2011.
Pre-season and friendlies
Aberdeen announced a series of pre-season friendlies in May 2010, including a tour of England and games in Scotland and Germany. The first pre-season friendly on 17 July 2010 against Highland Football League club Fraserburgh ended in a 1–3 defeat for Aberdeen. The following day, Aberdeen won 2–0 against Peterhead, with Mitchel Megginson and Michael Paton scoring. On 21 July, Aberdeen lost 0–1 to Dunfermline Athletic.Aberdeen's tour of England began in Tamworth on 24 July. Despite Aberdeen taking an early lead, Tamworth equalised early in the second half, and the game ended 1–1. Aberdeen's next game was against Port Vale, Aberdeen won 1–0 thanks to a Michael Paton penalty ten minutes before the end of the game. The tour of England concluded with a 0–1 defeat to Brighton & Hove Albion on 31 July 2010.
Aberdeen returned to Scotland to face Brechin City in a memorial match for former Brechin City chairman David Will on 4 August 2010. The result was a 2–2 draw, Fraser Fyvie and Andrew Considine scored for Aberdeen.
Aberdeen's final pre-season game was in Germany against 1. FC Kaiserslautern on 7 August 2010. Aberdeen lost 0–2 to the Bundesliga club.
Transfers
Seven new players arrived at Pittodrie in the summer transfer window, including Scotland international Paul Hartley, who was appointed as team captain. Three players were signed on loan between September 2010 and the end of the January transfer window, in addition to three permanent signings. Full-back Ricky Foster joined Aberdeen's rivals Rangers F.C. on transfer deadline day in August on a season-long loan, with striker Andrius Velička moving in the opposite direction.In
| Date | Player | From | Fee | Contract Length | Source |
| June 2010 |  Rory McArdle |  Rochdale | Free | Two years | |
| 5 July 2010 | Josh Magennis |  Cardiff City | Free | Two years | |
| 13 July 2010 | Mark Howard |  St Mirren | Free | One year | |
| 26 July 2010 | Scott Vernon | Colchester United | Free | Two years | |
| 26 July 2010 |  Yoann Folly | Plymouth Argyle | Free | Two years | |
| 28 July 2010 | Paul Hartley | Bristol City | Free | Two years | |
| 31 August 2010 |  Andrius Velička | Rangers | Loan | End of Season | |
| 6 September 2010 |  Nikola Vujadinović |  Udinese | Loan | End of Season | |
| 24 December 2010 | David McNamee | Plymouth Argyle | Free | Six months | |
| 31 December 2010 | Myles Anderson | Leyton Orient | Free | Six months | |
| 13 January 2011 | Robert Milsom | Fulham | Free | Six months | |
| 13 January 2011 | Nick Blackman | Blackburn Rovers | Loan | Six months | |
| 31 January 2011 | Steven Smith | Norwich City | Loan | Six months |
The end of the previous season saw three on-loan players return to their clubs. Paul Marshall, Jim Paterson and last season's top scorer Steven MacLean all left to go back to their parent club. Eight out-of-contract players departed Aberdeen on free transfers in the summer, including left-back Charlie Mulgrew, who rejoined Celtic, and former captain Mark Kerr, who joined Greek club Asteras Tripolis. Only one player left the club in the January transfer window, English defender Jerel Ifil, who was released from his contract.
Out
| Date | Player | To | Fee | Note | Source |
| 31 May 2010 | Charlie Mulgrew | Celtic | Free | Out of Contract | |
| 31 May 2010 | Gary McDonald | Hamilton Academical | Free | Out of Contract | |
| 6 June 2010 | Mark Kerr |  Asteras Tripolis | Free | Out of Contract | |
| 31 May 2010 | Stuart Duff | Inverness Caledonian Thistle | Free | Out of Contract | |
| 31 May 2010 | Paul Marshall | Manchester City | – | Loan Return | - |
| 31 May 2010 | Jim Paterson | Plymouth Argyle | – | Loan Return | - |
| 31 May 2010 | Steven MacLean | Plymouth Argyle | – | Loan Return | - |
| 31 May 2010 | Stuart Nelson | Notts County | Free | Out of Contract | |
| 1 July 2010 | Davide Grassi | Sorrento Calcio | Free | Out of Contract | |
| Jonathan Crawford | Montrose | Free | Out of Contract | ||
| Nicky Clark | Peterhead | Free | Out of Contract | ||
| 31 August 2010 | Ricky Foster | Rangers | Loan | End of season | |
| 31 January 2011 | Jerel Ifil | Free transfer | Released | ||
| 2 March 2011 | Mitchel Megginson | Brechin City | Loan | One month |