Below are the contents of your cart, where you can inspect the name, quantity, if the item is in stock or not and remove from cart if you need.

Your Shopping Cart is empty.


Please note that changing delivery zip code may result in removing your cart items. Confirm your delivery zip code and select your items again.

If you saved items on a previous visit, sign in to access your saved cart.


Continue Shopping

Your Wish List is empty.


If you saved items on a previous visit, sign in to access your wish list.


Continue Shopping

Extra Firm King Mattress

Skip to Filters


Why Buy an Extra Firm King Mattress from Rooms To Go?

If you and your partner like to sleep on an unwaveringly supportive surface while drifting off to dreamland on your back or stomach, consider settling in with a Rooms To Go extra firm king mattress. Made by some of the most popular and trusted manufacturers in the business, our mattresses boast independently flexing coil systems that deliver support where your body needs it most and eliminate motion transfer for sounder nights of rest. Reinforced edges maximize the useable area of our extra firm king mattresses, while foam encasements facilitate proper airflow. Many of our selections also feature gel-infused knit covers designed to envelop your skin in softness while wicking heat away from the body. Always constructed from quality materials, our extra firm mattresses never disappoint when it comes to providing deep support.