Delmar is a hamlet in the Town of Bethlehem, in Albany County, New York, United States.

"[5][6] Nathaniel Adams moved to the area in 1836 and, two years later, built a large hotel and made other improvements.

The name of the post office was changed to Adams Station in an attempt to relieve that confusion.

The Albany and Susquehanna Railroad, which had a station on Adams Street north of Kenwood Avenue, however, had chosen to change from Adamsville to Delmar.

In 1892, a petition by area residents to change the post office to match Delmar was accepted.

[8] The Patterson Farmhouse, United States Post Office, and Van Derheyden House are listed on the National Register of Historic Places.

[10] As a hamlet, the borders of Delmar are indeterminate, though generally the unincorporated village is considered to be centered on the intersection of Kenwood and Delaware avenues.

At Bridge Avenue, in the neighboring hamlet of Slingerlands, the CDP's border turns left, and then right onto Albany County Route 52 (Cherry Ave/Elm Ave).

After turning right onto Bethlehem Court, the border then travels in a straight northeastern line to intersect again at the Normanskill.