An infant sleep support supports a sleeping infant at its back and holds the infant so that the infant will sleep on its side. The sleep support has a fabric sheet on which the infant sleeps and a pillow against which the infant supports its back. The sleep support has a pillow cover with an opening on its underside, with the opening closeable by a flap attached to the back of the pillow cover. In one embodiment the sheet and the flap are of sufficient length for tucking both the sheet and the flap beneath a mattress on which the infant sleep support is laid.
