The Wilmington CDP covers a large area in the central part of the town of Wilmington, including the hamlet of Wilmington but extending west to include the hamlet of North Pole, east as far as Hardy Road, and south as far as Fox Farm Road.

The West Branch of the Ausable River flows from southwest to northeast through the center of the CDP.

New York State Route 86 runs through the center of the CDP, leading southwest 12 miles (19 km) to Lake Placid and east 5 miles (8 km) to Jay.

New York State Route 431 leads west from NY 86 near the center of Wilmington 8 miles (13 km) nearly to the summit of Whiteface Mountain.

[2] Most of the census-designated place is in the Lake Placid Central School District, while a portion is in Boquet Valley Central School District at Elizabethtown-Lewis-Westport.