Detailed information on every zip code in Middletown View all zip codes in NJ or use the free zip code lookup. Check the map below to check your ZIP Code. City Est. The people living in ZIP code 07748 are primarily white. Postal Service Look Up page.The following zip codes make up the Middletown area: Middletown covers 42 square miles and is divided into 12 different zip codes by the United States Postal Service. City of Middletown, NJ - MONMOUTH County New Jersey ZIP Codes. Check the list of New Jersey ZIP Code. Find your zip code by visiting the U.S. Zip Code 07748 - Middletown NJ New Jersey, USA - Monmouth County Stats and Demographics for the 07748 ZIP Code. It also has a slightly higher than average population density. Middletown Zip Code - Get the zipcode for Middletown in Monmouth, (NJ) New Jersey - zip-codez.com poblation Type ZIP Code; Middletown, NJ: 25.426: STANDARD: 07748 : Location of Middletown, NJ - USA. ZIP code 07748 is located in eastern New Jersey and covers a slightly less than average land area compared to other ZIP codes in the United States. New Jersey ZIP code map and New Jersey ZIP code list. load map. Explore Middletown, New Jersey zip code map, area code information, demographic, social and economic profile. ZIP Code » United States » New Jersey » Middletown, NJ. The location Middletown, NJ has 1 differents ZIP Codes. ZIP Code New Jersey. Middletown, NJ ZIP Code - United States.