Embodiments of a washable computer mouse are disclosed. In an embodiment, a water impermeable layer is sealably mounted to a housing so as to provide a water impermeable region and a water permeable region. Mouse circuitry, which includes a sensor and a light source and a responsive element, is positioned in the water impermeable region. A biased button is positioned in the water permeable region and is configured to engage the responsive element. In an embodiment, the mouse circuitry may be configured for wireless transmission of signals and may include a removable door that, in operation, sealably covers a replaceable power source. In an alternative embodiment, the housing may include an exposed connector and a plug that is configured to seal the connector may be attached to the housing by a tether.