Petroleum jelly or petrolatum is a byproduct of the refining of petroleum, made from the residue of petroleum distillation left in the still after all the oil has been vaporized.

Vaseline is a well-known brand of petroleum jelly originally produced by Chesebrough-Pond's, Inc., and currently by Unilever.

Petroleum jelly was discovered by Robert Chesebrough in 1859 in Brooklyn, New York. Chesebrough was intrigued by the paraffin-like substance that stuck to the drilling rigs. All the riggers hated the stuff because it caused the rigs to seize up, but they did use it on cuts and burns because it helped them heal faster. Chesebrough bottled the petroleum jelly and took it back to his office where he tested it on himself.

He gave out free samples across New York and within six months he had twelve wagons distributing the product, under the trade name Vaseline, across the state. The term Vaseline was coined as a combination of the German word for water, Wasser (pronounced Vahser), and the Greek word for oil, elaion.

In 1872, Chesebrough patented (U.S. No. 127,568) the process of making petroleum jelly. The patent said that distillation by heat under vacuum involves less heat than without the vacuum, and yields a better quality of jelly. The product is then filtered through bone char. The patent says its uses include currying, stuffing, and oiling all kinds of leather. The finest grade of petroleum is also adapted for use as a pomade for the hair. It is also used for treating chapped hands or lips, and toenail fungus.

In bullfighting, petroleum jelly is placed on a bull's eyes in order to hinder its sight.

Petroleum jelly used to be used as a sexual lubricant, particularly for anal sex, but it has the inconvenience of damaging latex condoms. The availability of water-based personal lubricants reduced this usage. It also used to be recommended for lubricating rectal thermometers or enema nozzles, but, again, water-based personal lubricants are better for that usage.