A combo washer dryer (also known more simply as a washer-dryer in the UK) is a combination in a single cabinet of a washing machine and a clothes dryer. It should not be confused with a "stackable" combination of a separate washing machine and a separate clothes dryer.

The main advantage of washer dryer combination units is their compactness. The small size of these machines, compared to the total space consumed by a separate washer and dryer, suits them to small homes, apartments, condominiums, and any place where space is an issue. Aside from having a small footprint, combo units also have a small height, allowing them to fit into confined places, like under a kitchen counter or in a closet.