CKTB is a radio station in St. Catharines, Ontario, Canada. Broadcasting at 610 AM, the station airs a News/Talk format. CKTB is housed in the former mansion of William Hamilton Merritt, the main promoter of the first Welland Canal, located on Yates Street in downtown St. Catharines. Its transmitters are located on Grassy Brook Road east of Port Robinson. In 1936, the station became a founding affiliate of CBC Radio and in 1944, affiliated with CBC's Dominion Network. The affiliation remained until the Dominion Network was dissolved in 1962.