,   www.LIHorseProperty.com , www.LongIslandSeniorsHousing.com , www.LongIslandGolfProperties.com,   www.LIHomeAuction.com ,  www.LIWaterfrontProperties.com , &  www.PrudentialElliman.com ,  www.prudential.com/realestate .   Southold Information Southold is a town in Suffolk County , New York , United States . It is located in the northeastern tip of the county, on the North Fork of Long Island .