A pantiliner (also panty liner or panty shield) is an absorbent piece of material used for feminine hygiene. It is worn in the gusset of a woman's panties. Some uses include: absorbency for daily vaginal discharge, light menstrual flow, tampon backup, spotting, post-intercourse discharge and slight urine leaks.

Pantiliners are related to sanitary napkins in their basic construction - but are usually much thinner and often narrower than pads. As a result they absorb much less liquid than pads - making them ideal for light discharge and everyday cleanliness, but generally unsuitable for menstrual flow or medium to heavy incontinence.

Pantiliners are found in an assortment of sizes, shapes, scents and portability options, ranging from tiny, compact liners to long, protective liners designed for heavy vaginal discharge and light days (light menstrual flow). There are even styles designed to fit with thong underwear.

Disposable pantiliners are made with a sticky adhesive on the back of the pad to hold them in place in the knickers, and some styles have 'wings' which wrap around the knickers, providing additional stability. Some popular brands of disposable pantiliners are Carefree, Always, and Kotex.

Reusable cloth pantiliners come in a variety of sizes, materials, patterns, colors, and absorbencies, and are usually secured to the underwear by wrap-around wings that snap together at the ends. Some popular brands of washable pantiliners are Lunapads and Gladrags. These are made of cotton (often organic), and can be washed and reused for years. See cloth menstrual pad for more information.