A disposable infant seat liner in accordance with the present invention includes an upper section, a middle section and a lower section. Plural shoulder strap receiving slotways are provided in the upper section. These slotways may be accessible from side edges of the infant seat liner. In one embodiment, three shoulder strap receiving positions are provided at each side of the upper section to accommodate shoulder straps of various infant seat designs. First and second leg or crotch strap receiving slotways are also provided in a lower section of the infant seat liner. In one specific embodiment, a Y-shaped leg strap receiving slotway is positioned below an upwardly facing U-shaped slotway. In another embodiment, the lower slotway is T-shaped. Arched side cuts may also be provided in the central section of the infant seat liner to accommodate waist straps and to facilitate fitting of the infant seat liner to an infant car seat. The slotways, cuts and slits may be selectively openable with perforations being provided for this purpose. In this latter case, a user need only open those perforations required to fit the infant seat liner to the user's particular infant seat.