3-in-One Oil is a general-purpose lubricating oil sold in small cans and squeezable containers for household and do-it-yourself use. It was originally formulated in 1894. Its name, given by the inventor George W. Cole of New Jersey, derives from the product's triple ability to "clean, lubricate and protect," originally for use on bicycles. The formula consists of pale spindle oil with a small amount of corrosion inhibitor and citronella oil (which gives the product its distinctive sharp odor). It remains a popular lubricant for bicycle chains.
The product changed ownership many times throughout the 20th century and was bought by its current owners, the WD-40 Company, in 1995. The current marketing slogan is "The Tool Kit In A Can" with the logo of the text "3 in" inside a large numeral "1".