Ilion lies southeast of the mountain Aigaleo, 6 km (4 mi) northwest of Athens city centre. Neighbouring municipalities are Agioi Anargyroi-Kamatero to the north and east, Petroupoli to the northwest and Peristeri to the south. The main streets are Fylis Avenue, Thivon Avenue, Idomeneos Street and Protesilaou Street.
Ilion hosts many athletic clubs in several sports. The most of them play in the amateur divisions. Presence or earlier presence in the higher divisions in their sport have the clubs Olympiakos Neon Liosion and Enosi Iliou.