Abstract: A bathtub pillow has a resilient cover with a bulged portion having a cavity and a flat area formed around the bulged portion; a resilient spacer received inside the cavity of the resilient cover; multiple sucking disks formed under the flat area of the resilient cover; and a bottom grating detachably attached to the resilient cover to enclose the resilient spacer inside the bulged portion. Thereby, the bathtub pillow is detachable and has no seams formed on the bathtub pillow, whereby the bathtub pillow can be kept clean. The resilient spacer props the bulged portion to make the bathtub pillow have a certain flexible rigidity to support a user's head. The bottom grating allows water inside the bathtub pillow to drain out to enable the bathtub pillow dry out after use.