Waterproof eyeliners are a type of cosmetic product that are applied around the eyes and will not smudge when wet. It is a good idea to wear waterproof eyeliner on hot days, when one might be sweating a lot, or at an event where one might be crying, such as a wedding. This way, the eyeliner will stay looking fresh and defined, not smudged or runny.

Waterproof eyeliners are available in liquid or pencil form. Liquid tends to last longer and be truly waterproof, but it is more difficult to apply liquid eyeliner in a smooth line. Liquid eyeliner also creates a more defined, severe line. It is generally recommended that one apply liquid eyeliner in a series of small dots on the eyelid, then simply connect the dots. This is simpler than trying to draw a straight line across the entire eyelid.

Pencil waterproof eyeliners are easier to apply, and can create a softer looking, more natural, and blended line on the eyes. Even waterproof versions of pencil eyeliners can smudge, however, so it is best to use pencil waterproof eyeliners only for days when one wants a long-lasting eyeliner, but may not need it to be truly waterproof. It may be necessary to try a few different brands to find one that holds up well all day long. Though some people use eyeshadow as a type of eyeliner applied with a small angled brush, this will not work as a waterproof eyeliner because eyeshadow is not designed to resist water.

Waterproof eyeliners typically need to be removed with makeup remover, and will not come off with soap and water. Do not scrub at the eyes to remove waterproof eyeliner, which can stretch the skin and cause wrinkles. Instead, apply makeup remover to a cotton ball or makeup sponge, and gently sweep it over the eyes until all of the makeup is removed. There are some makeup removers specifically designed to remove long-wearing makeup such as waterproof eyeliner.

Waterproof eyeliners are available in a number of different colors. Black, brown, and smokey gray are some of the most popular colors, but jewel tones are very popular as well. These may include blues, greens, or violets. These bright colors of eyeliners can really help to bring out the natural color of one's eyes. The bright, jewel toned colors often look the best in liquid eyeliner form, because they can be much more noticeable.