Slip-ons are typically low, lace-less shoes. The style which is most commonly seen, known as a loafer, slippers, or penny loafers in American culture, has a moccasin construction. One of the first designs was introduced in London by Wildsmith Shoes, called the Wildsmith Loafer. They began as casual shoes, but have increased in popularity to the point of being worn in America with business suits. Another design was introduced as Aurlandskoen (the Aurland Shoe) in Norway (early 20th century). They are worn in many situations in a variety of colors and designs, often featuring tassels on the front, or metal decorations (the 'Gucci' loafer).

A less casual, earlier type of slip-on is made with side goring (sometimes called a dress loafer). Made in the same shape as lace-up Oxfords, but lacking the laces, these shoes have elasticated inserts on the side which allow the shoe to be easily removed but remain snug when worn. This cut has its greatest popularity in Britain.