A lopapeysa or Icelandic sweater is an Icelandic style of sweater originating in early or mid-20th century, at a time when imports had displaced older and more traditional Icelandic clothing and people began to search for new ways to utilize the plentiful native wool. The design has since become a national icon for Icelandic cultural identity.

A sweater or pullover, also called a jersey or jumper, is a piece of clothing, typically with long sleeves, made of knitted or crocheted material that covers the upper part of the body. When sleeveless, the garment is often called a slipover, tank top, or sweater vest.