The following is a list of the largest cities and towns that contain the word “mouth” in their name. Most often, these places are situated at the mouth of a river, but a number of them are simply named for historical places or there city/town where the founders emigrated from. Plymouth is the best example of this as there are a number of “Plymouths” on the list, of which many of them were named in honor of Plymouth, Massachusetts and have no river mouth or outlet of significance. Nine (9) places named Plymouth are contained on the list, along with four (4) named Portsmouth, and three (3) named either Yarmouth or Falmouth.

- Dortmund, Germany = 587,696 (2020)
- Plymouth, England, UK = 256,384 (2011)
- Portsmouth, England, UK = 205,056 (2011)
- Bournemouth, England, UK = 183,491 (2011)
- Boca del Rio (Mouth of River), Mexico = 138,058 (2010)
- Boca Chica (Small Mouth), Dominican Republic = 123,510 (2012)
- Boca Raton (Rat’s Mouth), Florida = 99,805 (2019 est.)
- Portsmouth, Virginia = 94,398 (2019 est.)
- Plymouth, Minnesota = 79,768 (2019 est.)
- Tynemouth, England, UK = 67,519 (2011)
- Plymouth, Massachusetts = 56,468 (2010)
- Weymouth, Massachusetts = 53,743 (2010)
- Weymouth, England, UK = 53,068 (2011)
- Exmouth, England, UK =- 34,432 (2011)
- Dartmouth, Massachusetts = 34,032 (2010)
- Falmouth, Massachusetts = 31,531 (2010)
- Yarmouth, Massachusetts = 23,793 (2010)
- Portsmouth, New Hampshire = 21,927 (2019 est.)
- Falmouth, England, UK = 21,797 (2011)
- Wittmund, Germany = 20,405 (2020)
- Portsmouth, Ohio = 20,158 (2019 est.)
- Grangemouth, Scotland, UK = 16,650 (2016 est.)
- Teignmouth, England, UK = 15,129 (2011)
- Falmouth, Maine = 11,399 (2012 est.)
- Monmouth, Wales, UK = 10,508 (2011)
- Tangermünde, Germany = 10,299 (2020)
- Plymouth, Indiana = 9,982 (2019 est.)
- Plymouth, Michigan = 9,154 (2019 est.)
- Monmouth, Illinois = 8.886 (2019 est.)
- Cockermouth, England, UK = 8,761 (2011)
- Plymouth, Wisconsin = 8,731 (2019 est.)
- Yarmouth, Maine = 8,518 (2018 est.)
- Ueckermünde, Germany = 8,472 (2020)
- Plymouth, New Hampshire = 6,990 (2010)
- Yarmouth, NS, Canada = 6,518 (2016)
- Plymouth Meeting, Pennsylvania = 6,177 (2010)
- Plymouth, Pennsylvania = 5,794 (2019 est.)
- Dartmouth, England, UK = 5,064 (2011)
SOURCES:
- en.wikipedia.org for cities and towns in each nation
- translate.google.com