Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Memorial Field Park | Cemetery | 4 | Union | 40 37 06 N | 074 13 59 W |
| Merck and Company Heliport | Airport | 6 | Union | 40 36 46 N | 074 16 04 W |
| Merck Athletic Field | Park | 6 | Union | 40 36 31 N | 074 15 40 W |
| Metropolitian Seventh Day Adventist Church | Church | 41 | Union | 40 36 10 N | 074 26 11 W |
| Mickey Walker Community Center | Building | 41 | Union | 40 40 01 N | 074 11 56 W |
| Middlesex Reservoir | Reservoir | 5 | Union | 40 36 46 N | 074 18 08 W |
| Middlesex Reservoir Dam | Dam | 5 | Union | 40 36 46 N | 074 18 08 W |
| Milltown | Populated Place | 28 | Union | 40 42 07 N | 074 18 60 W |
| Milton Campbell Field | Park | 41 | Union | 40 38 19 N | 074 24 03 W |
| Milton Lake Dam | Dam | 2 | Union | 40 36 22 N | 074 17 54 W |
| Milton Lake Park | Park | 2 | Union | 40 36 20 N | 074 17 54 W |
| Mindowaskin Park | Park | 43 | Union | 40 39 21 N | 074 20 51 W |
| Miracle Baptist Church | Church | 41 | Union | 40 38 02 N | 074 24 24 W |
| Moravian Church | Church | 41 | Union | 40 39 51 N | 074 12 16 W |
| Morse Creek | Stream | | Union | 40 37 29 N | 074 14 39 W |
| Morses Creek | Stream | | Union | 40 38 02 N | 074 12 07 W |
| Mount Calvary Cemetery | Cemetery | 6 | Union | 40 38 01 N | 074 14 05 W |
| Mount Olive Baptist Church | Church | 41 | Union | 40 36 49 N | 074 25 36 W |
| Mount Olive Temple | Church | 41 | Union | 40 42 44 N | 074 21 18 W |
| Mount Zion Chapel | Church | 41 | Union | 40 39 56 N | 074 12 14 W |
| Mount Zion Pentecostal Church | Church | 41 | Union | 40 39 52 N | 074 12 23 W |
| Mountain Park Elementary School | School | 41 | Union | 40 40 05 N | 074 27 04 W |
| Mountainside | Populated Place | 46 | Union | 40 40 20 N | 074 21 27 W |
| Mountainside School | School | 41 | Union | 40 40 20 N | 074 21 21 W |
| Mravlag Manor (subdivision) | Populated Place | 41 | Union | 40 38 48 N | 074 12 47 W |
| Muhlenberg Regional Medical Center | Hospital | 30 | Union | 40 36 25 N | 074 24 08 W |
| Murray Hill | Populated Place | 76 | Union | 40 41 43 N | 074 24 04 W |
| Murray Hill Station | Locale | 76 | Union | 40 41 42 N | 074 24 14 W |
| Myles J McManus Elementary School | School | 18 | Union | 40 38 15 N | 074 16 33 W |
| N M Butler Elementary School | School | 6 | Union | 40 40 30 N | 074 13 02 W |
| Nancy Thompson Library | Building | 41 | Union | 40 40 42 N | 074 13 60 W |
| Netherwood | Populated Place | 33 | Union | 40 37 50 N | 074 24 44 W |
| Netherwood Golf Course (historical) | Locale | 41 | Union | 40 37 33 N | 074 22 52 W |
| Netherwood Station | Locale | 36 | Union | 40 37 45 N | 074 24 11 W |
| New Academic Building | Building | 41 | Union | 40 40 49 N | 074 14 02 W |
| New Academic Building 2 | Building | 41 | Union | 40 40 44 N | 074 14 02 W |
| New Bethel Baptist Church | Church | 41 | Union | 40 39 40 N | 074 12 07 W |
| New Providence | Populated Place | 66 | Union | 40 41 54 N | 074 24 06 W |
| New Providence High School | School | 41 | Union | 40 42 03 N | 074 24 31 W |
| New Providence Station | Locale | 89 | Union | 40 42 40 N | 074 23 14 W |
| New Zion Baptist Church | Church | 41 | Union | 40 39 36 N | 074 11 58 W |
| New Zion Baptist Church | Church | 41 | Union | 40 40 00 N | 074 11 47 W |
| Nomahegan Brook | Stream | | Union | 40 40 32 N | 074 18 46 W |
| Nomahegan Park | Park | 22 | Union | 40 40 10 N | 074 18 51 W |
| North Elizabeth Station | Locale | 41 | Union | 40 40 50 N | 074 12 20 W |
| North Elizabeth Station Elizabeth Post Office | Post Office | 41 | Union | 40 40 52 N | 074 12 32 W |
| North of Shooters Island Reach | Channel | -3 | Union | 40 38 48 N | 074 09 58 W |
| North Rahway Station | Locale | 6 | Union | 40 36 47 N | 074 16 12 W |
| Number 1 Elementary School | School | 12 | Union | 40 38 08 N | 074 15 36 W |
| Number 2 Elementary School | School | 5 | Union | 40 37 18 N | 074 14 16 W |
| Number 4 Elementary School | School | 6 | Union | 40 38 52 N | 074 14 24 W |
| Number 5 Elementary School | School | 11 | Union | 40 38 29 N | 074 15 10 W |
| Number 6 Elementary School | School | 7 | Union | 40 37 47 N | 074 14 54 W |
| Number 8 Elementary School | School | 8 | Union | 40 37 41 N | 074 15 29 W |
| O'Brien Park | Park | 41 | Union | 40 39 24 N | 074 12 16 W |
| Oak Knoll School of the Holy Child | School | 93 | Union | 40 43 14 N | 074 22 02 W |
| Oak Ridge Country Club | Locale | 26 | Union | 40 36 18 N | 074 20 44 W |
| Oaks Memorial Church | Church | 41 | Union | 40 42 42 N | 074 20 53 W |
| Oakwood Park | Populated Place | 66 | Union | 40 42 34 N | 074 24 25 W |
| Oheb Sholem Cemetery | Cemetery | 18 | Union | 40 41 43 N | 074 12 45 W |
| Orange Avenue Elementary School | School | 41 | Union | 40 40 12 N | 074 17 53 W |
| Oratory School | School | 55 | Union | 40 45 09 N | 074 22 06 W |
| Oratory School for Boys | School | 82 | Union | 40 43 25 N | 074 22 04 W |
| Our Lady of Peace Church | Church | 41 | Union | 40 42 10 N | 074 24 21 W |
| Our Lady of Peace School | School | 65 | Union | 40 42 09 N | 074 24 22 W |
| Overlook | Populated Place | 120 | Union | 40 42 45 N | 074 21 06 W |
| Overlook Hospital | Hospital | 121 | Union | 40 42 43 N | 074 21 15 W |
| Park Methodist Episcopal Church | Church | 41 | Union | 40 40 17 N | 074 12 26 W |
| Park Middle School | School | 45 | Union | 40 38 49 N | 074 23 39 W |
| Park Street Chapel | Church | 41 | Union | 40 39 43 N | 074 14 34 W |
| Park Village | Populated Place | 28 | Union | 40 39 05 N | 074 17 27 W |
| Paul Korlesky Park | Park | 41 | Union | 40 41 28 N | 074 13 47 W |
| Peach Orchard Brook | Stream | | Union | 40 37 46 N | 074 13 44 W |
| Peach Orchard Park | Park | 41 | Union | 40 38 50 N | 074 14 29 W |
| Penn School | School | 6 | Union | 40 38 57 N | 074 11 45 W |
| Penske Heliport | Airport | 24 | Union | 40 33 26 N | 074 27 60 W |
| Perth Amboy Junction | Populated Place | 6 | Union | 40 35 53 N | 074 17 08 W |
| Peterstown Elementary School | School | 6 | Union | 40 39 26 N | 074 12 15 W |
| Piles Creek | Stream | | Union | 40 37 11 N | 074 12 17 W |
| Pilgrim Baptist Church | Church | 41 | Union | 40 42 44 N | 074 20 41 W |
| Pingry School (historical) | School | 12 | Union | 40 40 47 N | 074 13 28 W |
| Pioneer Homes (subdivision) | Populated Place | 41 | Union | 40 39 06 N | 074 11 01 W |
| Plainfield | Populated Place | 34 | Union | 40 38 01 N | 074 24 27 W |
| Plainfield High School | School | 41 | Union | 40 36 42 N | 074 24 46 W |
| Plainfield Public Library | Building | 41 | Union | 40 36 48 N | 074 24 54 W |
| Plainfield Station | Locale | 31 | Union | 40 37 07 N | 074 25 09 W |
| Port Elizabeth Marine Terminal | Locale | 3 | Union | 40 40 27 N | 074 08 37 W |
| Pralls Island Reach | Channel | -3 | Union | 40 36 45 N | 074 12 11 W |
| Presbyterian Church at New Providence | Church | 41 | Union | 40 42 23 N | 074 24 24 W |
| Progressive Baptist Church | Church | 41 | Union | 40 36 16 N | 074 16 32 W |
| Pumpkin Patch Brook | Stream | | Union | 40 36 45 N | 074 20 34 W |
| Rahway | Populated Place | 5 | Union | 40 36 29 N | 074 16 40 W |
| Rahway Cemetery | Cemetery | 12 | Union | 40 37 03 N | 074 17 11 W |
| Rahway City Hall | Building | 41 | Union | 40 36 31 N | 074 16 40 W |
| Rahway Engine Company Number 5 | Building | 41 | Union | 40 36 26 N | 074 17 27 W |
| Rahway High School | School | 12 | Union | 40 36 39 N | 074 17 39 W |
| Rahway Hospital | Hospital | 41 | Union | 40 36 47 N | 074 17 27 W |
| Rahway Middle School | School | 41 | Union | 40 36 52 N | 074 17 42 W |
| Rahway Public Library | Building | 41 | Union | 40 36 44 N | 074 16 39 W |
| Rahway River | Stream | | Union | 40 35 38 N | 074 12 18 W |
| Rahway River Parkway | Park | 23 | Union | 40 40 45 N | 074 19 06 W |
| Rahway Station | Locale | 5 | Union | 40 36 20 N | 074 16 36 W |
| Rahway Theatre | Building | 41 | Union | 40 36 39 N | 074 16 35 W |
| Rahway Waterworks | Locale | 41 | Union | 40 37 04 N | 074 17 21 W |
| Rahway Yacht Club | Locale | 41 | Union | 40 36 13 N | 074 15 48 W |
| Raritan Road Riding Academy (historical) | School | 41 | Union | 40 37 17 N | 074 19 28 W |
| Ravens Nest Heliport | Airport | 32 | Union | 40 41 25 N | 074 18 27 W |
| Redeemer Lutheran Church | Church | 41 | Union | 40 39 07 N | 074 21 14 W |
| Reformed Church of Linden | Church | 41 | Union | 40 38 04 N | 074 15 32 W |
| Regent Theatre | Building | 41 | Union | 40 39 48 N | 074 12 52 W |