Monmouth is located in Warren County, IL. The population is 9,659, making Monmouth the largest city in Warren County.
There are 9 public schools in Monmouth with an average Homefacts rating of C+. The total crime rate for Monmouth is moderate , and there are 0 registered sex offenders residing in the city. Unemployment in Monmouth is moderate and the median home sales price is $0. Detailed and up-to-date Monmouth property reports are available for any property address.