Rarity Bay is a golf course community and census-designated place in Loudon and Monroe counties, Tennessee, United States. It was first listed as a CDP prior to the 2020 census. its population during the census was 885. It is in the southern part of Loudon County and the northern part of Monroe County, occupying a peninsula in Tellico Reservoir, with the Little Tennessee River to the southeast and the cove of Bat Creek to the northwest.