Town Hall Address 205 Claremont Ave. Montclair, NJ 07042-9998 United States- Essex County Website https://www.montclairnjusa.org/ County Clerk 973-509-4900 205 Claremont Ave. Montclair, NJ 07042-9998 United States County Manager 973-509-4926 205 Claremont Ave. Montclair, NJ 07042-9998 United States Assessor 973-509-4918 205 Claremont Ave. Montclair, NJ 07042-9998 United States Tax Collector 973-509-4921 205 Claremont Ave. Montclair, NJ 07042-9998 United States Attorney 973-509-4932 205 Claremont Ave. Montclair, NJ 07042-9998 United States Mayor 973-744-1400 205 Claremont Ave. Montclair, NJ 07042-9998 United States Municipal Court 973-509-4774 647 Bloomfield Ave. Montclair, NJ 07042 United States Town Hall Hours 8:30 a.m. - 4:30 p.m. County Essex