Do your sheets fit on a mattress that are more than 11” thick? January 28, 2022 14:58 Yes. Our sheets are designed to fit mattresses with a thickness of 11 inches to 14 inches. Related articles Do I need a mattress protector? Will the mattress protector make me sleep hot? Is the mattress protector hypoallergenic? Will your products have that “factory” smell? What is your return policy for sleep accessories? Comments 0 comments Article is closed for comments.