The sippy cup refers to cups with a plastic lid and spout, used to help train babies to drink from cups. Richard Belanger, who sold his design to Playtex, created one of the earliest designs of the sippy cup®. Variants of the design are still marketed as the Sipster®.

It can be very challenging for babies under the age of one to drink from a regular cup. Controlling tipping the cup up to get the drink takes fine motor control that many babies lack. Drinking from a regular cup can lead to choking and spluttering on liquids when too much liquid is taken in. Further, babies notoriously spill their drinks and may even enjoy overturning a cup to see its contents flow out. This is natural baby behavior that is somewhat counteracted by using a sippy cup.

To minimize spilling, a sippy cup lid may have a spout that requires some suction from the baby in order to release the liquids. Some brands use a plastic or rubber valve that fits into the spout to keep it leak-proof. This means that if the cup is overturned, liquid won’t necessarily leak from the cup. The lids of the sippy cup designed for young babies, perhaps at 5-8 months old, also may mimic a bottle or breast nipple in shape. Some feel this design helps transition the baby from breast or bottle-feeding.

Once the baby has gotten the hang of using a cup with a nipple type spout, a more advanced spout can be used. Some parents never use the nipple spout on sippy cups but merely introduce a small sippy cup with a semi-prismatic shaped spout. Another feature sometimes included in the sippy cup is a rounded and slightly weighted bottom. Playtex® manufactures these as tumble mates, or they may be more generically called Tommy Tippy cups. If the cup is knocked over, it springs back up.

As children get a little older, parents still may want to minimize large spills using simple plastic cups with a lid and spout. These don't require suction but still disperse liquid more slowly than would a regular cup. Spilling at a slower rate allows parents to quickly catch small spills.

When to introduce the sippy cup is a debatable matter. Some parents start when babies are about four or five months old, and other parents wait until a baby is 8-10 months old prior to trying a sippy cup. Earliest liquids, especially if the baby is under a year old and still nursing or taking formula should simply be water, formula or breastmilk. When baby gets mobile, don’t allow the baby to travel with a sippy cup or a bottle. Spills can occur, and baby can accidentally fall on the cup and cut the mouth.

Use care when washing sippy cup lids. Any parent who has used a sippy cup can relate tales of how the sippy cup lid melted in the dishwasher. Try to keep lids on the top rack of the dishwasher, and if necessary, wedge them between two cups to prevent them from falling below the lower rack and onto the heating element.