A window seat is a seating area in an alcove or nook which is lined with windows. Window seats have romantic associations, as many people idealize the sense of luxury and spare time which a window seat suggests. Typically, a window seat is installed in an area with an attractive view, so that someone seated in it can enjoy the beauty of the outdoors while working on a project which requires abundant natural light such as knitting. Window seats are also used for reading or simply enjoying a respite from daily life. Many homes are built with window seats in mind, but it is also possible to install one at relatively low cost.

A conventional window seat is located in an alcove such as the space provided by bay windows. This prevents the window seat from jutting out into the room and interrupting the feel of open space in the house, while also creating a nook for the window seat which can feel like a retreat. In some cases, a window seat may even be lined with curtains so that the person seated in it can close off the rest of the house. Most commonly, a window seat is built with cushioned raised benches to sit on, and it is typical to include storage under the bench.

In a small window seat, there will be enough room for one or two people to sit with books or small projects. Larger window seats may be designed to accommodate seated diners, creating a dining nook or alcove, or a table to be used as a workspace. The only hard and fast rule about the layout of a window seat is that it must include built in bench seating in order to be considered a window seat.

Many Victorian homes have built in window seats, as do other homes with bay windows and available window lined nooks. Homeowners who want to install a window seat without remodeling the house can also built one relatively cheaply, using prefabricated cabinets to create a seating and storage area under a window. To make the window seat feel more like a nook, shelving and cabinets can line the window seat, creating a small area of retreat along with a back rest.

While a window seat is typically padded, it can also be accented with cushions or throws. In window seats which lift up, covering the seat in an assortment of pillows may not be practical. In window seats which have cabinets accessed through opening or sliding doors, the seats can be covered in an assortment of materials, as they will not be disturbed every time someone needs something from inside the window seat.