| Club: | Guingamp |
| Season: | 2018–19 |
| Stadium: | Stade de Roudourou |
| Mgrtitle: | Manager |
| Manager: | Jocelyn Gourvennec |
| Chairman: | Bertrand Desplat |
| League: | Ligue 1 |
| League Result: | 20th (relegated) |
| Cup1: | Coupe de France |
| Cup1 Result: | Round of 16 |
| Cup2: | Coupe de la Ligue |
| Cup2 Result: | Runners-up |
| League Topscorer: | Marcus Thuram (9) |
| Season Topscorer: | Marcus Thuram (13) |
| Highest Attendance: | League/All: 19,003 (18 August vs. Paris Saint-Germain) |
| Lowest Attendance: | League: 12,327 All: 8,768 (7 February vs. Lyon (CdF)) |
| Largest Win: | 2–0 at Monaco (22 December) 4–2 v. Stade Pontivyen 5 January, CdF) |
| Largest Loss: | 0–9 at PSG (19 January) |
| Prevseason: | 2017–18 |
| Nextseason: | 2019–20 |
| Pattern La1: | _guingamp1819h |
| Pattern B1: | _guingamp1819h |
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The 2018–19 En Avant de Guingamp season was the 106th professional season of the club since its creation in 1912.
See main article: 2018–19 Ligue 1.
See main article: 2018–19 Coupe de France.
See main article: 2018–19 Coupe de la Ligue.