Rexford is a city in Thomas County, Kansas, United States. As of the 2020 census, the population of the city was 197. Rexford was founded in a…Rexford is a city in Thomas County, Kansas, United States. As of the 2020 census, the population of the city was 197. Rexford was founded in approximately 1887. It was named in honor of a member of the Rexford family who died in a fire that engulfed the family home. They were some of the first settlers in the area and had been there for years.