The Frenchman clocked a time of three minutes 45.60 in the final, half a second better than Norway's Henrik Ingebritsen, who claimed silver in a photo finish with Britain's Chris O'Hare.
Mekhissi-Benabbad became the most talked-about athlete of the championships for his celebration during the final stretch of the 3000m steeplechase, in which he pulled off his shirt before the final hurdle and stormed over the line with arms aloft.
Despite his huge margin of victory he was thrown out of the event and stripped of gold for not having crossed the line while wearing his number - a decision which split fans, with many praising him for his moment of entertaining chutzpah and others horrified at what they saw as a cheap stunt which devalued the event.
Britain's Martyn Rooney collected a second gold of the European Championships as he anchored the British quartet home in the 4x400m relay.
1500m men's final results
1. Mahiedine Mekhissi-Benabbad (France) 3:45.60
2. Henrik Ingebrigtsen (Norway) 3:46.10
3. Chris O'Hare (Britain) 3:46.18
4. Paul Robinson (Ireland) 3:46.35
5. Homiyu Tesfaye (Germany) 3:46.46
6. David Bustos (Spain) 3:46.92
7. Timo Benitz (Germany) 3:47.26
8. Tarik Moukrime (Belgium) 3:47.33
9. Soufiane El Kabbouri (Italy) 3:51.98
10. Florian Orth (Germany) 3:54.35
11. Stanislav Maslov (Ukraine) 3:54.59
12. Charlie Grice (Britain) 4:04.81
. Ciaran O'Lionaird (Ireland) DNF
. Jakub Holusa (Czech Republic) DNS
- Sports & Recreation
- Chris O'Hare