Sylvester is a lunar impact crater that is located near the north pole of the Moon, along the northern limb in the libration zone. It lies just to the south-southeast of the craters Grignard and Hermite; the latter of which is within one crater diameter of the pole. South of Sylvester is Pascal. Due to its location, Sylvester receives sunlight at only a low angle. This crater is generally circular, with a sharp-edged rim that has received only a moderate amount of wear. There are no craters of note along the rim, although Sylvester intrudes into a smaller, shallow-rimmed crater to the southeast. The interior floor is relatively flat, but punctuated by several tiny craters. At the midpoint is a small central peak.

Satellite craters

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Sylvester.