Although the name "Mountain Lakes" was no doubt chosen for its rustic appeal, it aptly describes the predominant physical characteristics of the town. Mountain Lakes is located in north-central New Jersey where the.rolling hills of the New Jersey's Piedmont region meet the rocky outcroppings of the Highlands. Mountain Lakes is approximately 35 miles due west of New York City, 12 miles northwest of Newark, New Jersey's largest city, and 9 miles north of Morristown, the county seat.

The borough is situated near the center of Morris County, one of the state's most populous and rapidly growing areas. Mountain Lakes lies just northwest of the intersection of Routes I-287, I-80 and north of NJ State Route 46, a major commercial thoroughfare which forms part of the Borough's southern boundary.