A toilet seat is a bathroom furniture consist of a seat and lid of a toilet bowl. The lid when down serves as a seat for other purposes, such as a seat to sit on while one is warming up a shower, cutting toenails or drying oneself after a bath or shower.

Toilet seats come in a wide variety of shapes, from the normal molded wood to the more expensive plastic oval seat to the opened-front seat often seen in public restrooms. They can be made of porcelain, plastic, steel, ivory or molded wood. Some metal toilets, such as those in many jails and prisons, have built-in toilet seats that do not lift so that the inmate does not fashion it into a weapon or escape tool.

Toilet seats found in homes and homelike settings generally have fully circular seats with no gap. While most of them are white, they come in a variety of colors and styles that can be custom purchased to fit the design of the particular bathroom. Some are made of various types of fancy wooden materials, like oak or walnut, and others are made soft for added comfort. At various times, printed seats, with multi-colored designs, such as floral or newsprint, have been fashionable.

In the early 20th century, it was fairly commonplace for toilet seats found in public restrooms to be black. This added a touch of style to the design of the washroom. However, since the second half of the century, the general preference in the United States has been to construct public restrooms with white toilet seats, thereby giving a brighter appearance.