A sun lounger is a chair-like device, typically placed in a patio, garden, or swimming pool deck, or used as beach-side outdoor furniture.

They are often constructed from wood, formed plastic, or metal and outdoor fabrics. They have designed adjustable backs for people to lie down, or sit up on, (recline) while relaxing. Somewhat like a deckchair and bed-like in nature, the rear surface can be up to allow the user to sit up and read, or it can be reclined to a flat surface to allow sleeping in the horizontal position.