Warren County, New Jersey Cities (2025)

24 cities

City	Rank	2025 Pop. ↓	2020 Pop.	Change	Density	Area (mi²)	Type
Washington township	1	49,698	48,720	0.32%	2,328	21.35	Township
Washington township	2	18,328	18,148	0.32%	411	44.58	Township
Phillipsburg	3	15,388	15,224	0.19%	4,822	3.19	Town
Hackettstown	4	10,131	10,232	0.03%	2,805	3.61	Town
Lopatcong township	5	9,503	8,788	0.38%	1,299	7.32	Township
Washington township	6	9,309	9,267	0.25%	3,152	2.95	Township
Mansfield township	7	7,970	7,772	0.59%	269	29.59	Township
Washington borough	8	7,349	7,281	0.1%	3,740	1.97	Borough
Washington township	9	6,938	6,494	1.15%	386	17.96	Township
Blairstown township	10	5,785	5,698	0.24%	194	29.89	Township
Independence township	11	5,549	5,459	0.27%	280	19.83	Township
Allamuchy township	12	5,470	5,345	0.22%	274	19.99	Township
White township	13	4,764	4,602	0.63%	174	27.37	Township
Delaware township	14	4,583	4,544	0.13%	125	36.66	Township
Pohatcong township	15	3,298	3,240	0.34%	247	13.37	Township
Knowlton township	16	2,944	2,887	0.31%	119	24.72	Township
Liberty township	17	2,696	2,665	0.15%	231	11.67	Township
Belvidere	18	2,548	2,517	0.24%	1,758	1.45	Town
Harmony township	19	2,531	2,495	0.12%	107	23.75	Township
Oxford township	20	2,480	2,441	0.32%	416	5.96	Township
Alpha borough	21	2,360	2,326	0.26%	1,404	1.68	Borough
Frelinghuysen township	22	2,236	2,197	0.27%	95	23.62	Township
Hope township	23	1,863	1,832	0.32%	103	18.09	Township
Hardwick township	24	1,612	1,593	0.06%	43	37.52	Township

Warren County Cities Summary

Washington township is the largest city in Warren County, with a population of 49,698.