| P | # | Player | Born | Height | Weight | Contract | |
|---|---|---|---|---|---|---|---|
| GK | Artur Boruc | 1980-02-20 | 193 | 88 | 2018-06-30 | ||
| GK | Dominic Cervi | 1986-07-09 | 198 | 93 | |||
| GK | Lukasz Zaluska | 1982-06-16 | 190 | 88 | |||
| D | Andreas Hinkel | 1982-03-26 | 183 | 74 | |||
| D | Danny Fox | 1985-05-29 | 183 | 79 | 2015 jun | ||
| D | Darren O'Dea | 1987-02-04 | 185 | 82 | |||
| D | Edson Braafheid | 1983-04-08 | 176 | 71 | 2017-06-30 | ||
| D | Gary Caldwell | 1982-04-12 | 180 | 75 | 2014 jun | ||
| D | Glenn Loovens | 1983-09-22 | 177 | 74 | |||
| D | Jos Hooiveld | 1983-04-22 | 193 | 82 | 2018-06-30 | ||
| D | Josh Thompson | 1991-02-25 | 193 | 76 | Loan | ||
| D | Lee Naylor | 1980-03-19 | 175 | 71 | |||
| D | Paul Caddis | 1988-04-19 | 170 | 67 | |||
| D | Stephen McManus | 1982-09-10 | 188 | 83 | 2013 | ||
| D | Thomas Rogne | 1990-06-29 | 193 | 82 | 2017-12-31 | ||
| M | Aiden McGeady | 1986-04-04 | 177 | 71 | 2020-06-30 | ||
| M | Barry Robson | 1978-11-07 | 180 | 70 | |||
| M | Landry N'Guemo | 1985-11-28 | 172 | 70 | |||
| M | Mark Millar | 1988-02-23 | 167 | ||||
| M | Patrick McCourt | 1983-12-16 | 182 | 70 | |||
| M | Ryan Conroy | 1987-04-28 | |||||
| M | Scott Brown | 1985-06-25 | 165 | 64 | 2015 | ||
| M | Shaun Maloney | 1983-01-24 | 170 | 70 | 2017-06-30 | ||
| M | Simon Ferry | 1988-01-11 | 175 | 70 | |||
| M | Sung-Yong Ki | 1989-01-24 | 187 | 75 | |||
| M | Willo Flood | 1985-04-10 | 168 | 62 | |||
| F | Ben Hutchinson | 1987-11-27 | 180 | 79 | |||
| F | Christopher Killen | 1981-10-08 | 183 | 80 | 2010 | ||
| F | Cillian Sheridan | 1989-02-23 | 196 | 87 | |||
| F | Diomansy Kamara | 1980-11-08 | 181 | 72 | |||
| F | Georgios Samaras | 1985-02-21 | 192 | 85 | 2016 jun | ||
| F | Greig Spence | 1992-07-06 | |||||
| F | James Forrest | 1991-07-07 | 170 | ||||
| F | Marc-Antoine Fortuné | 1981-07-02 | 183 | 76 | 2015 jun | ||
| F | Morten Rasmussen | 1985-01-31 | 185 | 77 | 2019-06-30 | ||
| F | Niall McGinn | 1987-07-20 | 173 | 70 | 2017-06-30 | ||
| F | Robbie Keane | 1980-07-08 | 175 | 73 | |||
| F | Scott McDonald | 1983-08-21 | 172 | 78 |
| Date | Player | From | To | Status | Src |
|---|---|---|---|---|---|
| 23.Apr | Kundai Benyu (M) | Helsingborgs IF | Celtic FC | Confirmed | |
| 27.Feb | Kundai Benyu (M) | Celtic FC | Helsingborgs IF | Confirmed | |
| 27.Feb | Kundai Benyu (M) | Ipswich Town | Celtic FC | Confirmed | |
| 30.Jun | Odsonne Edouard (F) | Celtic FC | Paris Saint-Germain F.C. | Confirmed | |
| 30.Jun | Patrick Roberts (M) | Celtic FC | Manchester City | Confirmed | |
| 30.Jun | Scott Allan (M) | Rotherham United | Celtic FC | Confirmed | |
| 18.Jan | Mikael Lustig (D) | Celtic FC | Celtic FC | Extension | |
| 30.Aug | Cristian Gamboa (D) | West Bromwich Albion | Celtic FC | Confirmed | |
| 26.Aug | Stefan Johansen (M) | Celtic FC | Fulham FC | Confirmed | |
| 7.Aug | Scott Sinclair (M) | Aston Villa FC | Celtic FC | Confirmed |