Most populated municipalities

The 20 municipalities in Iwate Ken with the most residents, and the 20 with the fewest, out of 35 with a published figure.

	Municipality	Prefecture	Postal code	Residents
1	Nagasaki Prefecture	Iwate Ken	028-1351	1,307,309
2	Morioka	Iwate Ken	020-0833	290,553
3	Arakawa	Iwate Ken	028-1303	217,891
4	Nakamura-ku	Iwate Ken	028-8334	134,698
5	Ōshū-shi	Iwate Ken	023-1115	112,531
6	Ichinoseki	Iwate Ken	021-0867	111,824
7	Hanamaki	Iwate Ken	025-0244	92,815
8	Kitakami	Iwate Ken	024-0076	92,348
9	Takizawa	Iwate Ken	020-0690	56,050
10	Miyako	Iwate Ken	027-0301	50,855
11	Ōfunato	Iwate Ken	022-0211	34,558
12	Kamaishi	Iwate Ken	026-0041	33,061
13	Kuji	Iwate Ken	028-0063	32,813
14	Ōkawa-shi	Iwate Ken	028-2232	32,609
15	Shiwa	Iwate Ken	028-3448	32,036
16	Ōmachi-shi	Iwate Ken	028-1112	25,883
17	Tōno-shi	Iwate Ken	028-0531	25,181
18	Ninohe	Iwate Ken	028-6868	25,083
19	Hachimantai	Iwate Ken	028-7564	23,742
20	Rikuzentakata	Iwate Ken	029-2205	18,182

Least populated municipalities

	Municipality	Prefecture	Postal code	Residents
1	Kitayama	Iwate Ken	028-8402	408
2	Fudai	Iwate Ken	028-8335	2,489
3	Tanohata	Iwate Ken	028-8400	3,008
4	Sumita	Iwate Ken	029-2300	4,997
5	Nishiwaga	Iwate Ken	029-5500	5,059
6	Kunohe	Iwate Ken	028-7901	5,256
7	Hiraizumi	Iwate Ken	029-4192	7,178
8	Ando	Iwate Ken	028-1105	7,196
9	Iwaizumi	Iwate Ken	027-0501	8,549
10	Nagashima	Iwate Ken	029-4101	9,654
11	Nakayama	Iwate Ken	028-8344	10,617
12	Otsuchi	Iwate Ken	028-1131	10,719
13	Iwate	Iwate Ken	020-0554	12,078
14	Yamada	Iwate Ken	028-1321	14,388
15	Kanegasaki	Iwate Ken	029-4500	15,337
16	Rikuzentakata	Iwate Ken	029-2205	18,182
17	Hachimantai	Iwate Ken	028-7564	23,742
18	Ninohe	Iwate Ken	028-6868	25,083
19	Tōno-shi	Iwate Ken	028-0531	25,181
20	Ōmachi-shi	Iwate Ken	028-1112	25,883

Most populated municipalities — All of Japan

One row per municipalities. The figures are published by municipality, so every postal code inside one shares them; the postal code shown is one of that municipality's.