Silver Lake is a city in Shawnee County, Kansas, United States. As of the 2020 census, the population of the city was 1,345. Silver Lake was fo…Silver Lake is a city in Shawnee County, Kansas, United States. As of the 2020 census, the population of the city was 1,345. Silver Lake was founded in 1868. It was named from the lake upon which it was situated. In the spring of 1871, the city of Silver Lake was incorporated.