A lavvu (or Northern Sami: lávvu, Lule Sami: låvdagoahte, Inari Sami: láávu, Skolt Sami: kååvas, Kildin Sami: коавас (kåvas), Finnish: kota or umpilaavu, Norwegian: lavvo or sametelt, and Swedish: kåta) is a temporary dwelling used by the Sami people of northern extremes of Northern Europe. It has a design similar to a Native American tipi but is less vertical and more stable in high winds. It enables the indigenous cultures of the treeless plains of northern Scandinavia and the high arctic of Eurasia to follow their reindeer herds. It is still used as a temporary shelter by the Sami, and increasingly by other people for camping. It should not be confused with the goahti, another type of Sami dwelling, or the Finnish laavu.

There are several historical references that describe the lavvu structure used by the Sami. These structures have the following in common:

No historical record has come to light that describes the Sami using a single-pole structure claimed to be a lavvu, or any other Scandinavian variant name for the structure. The definition and description of this structure has been fairly consistent since the 17th century and possibly many centuries earlier.

The goahti, also used by the Sami, has a different pole configuration. While trees suitable to make lavvu poles are quite easy to find and often left at the site for later use, the four curved poles of the goahti have to be carried.

The traditional lavvu consists of two types of wooden poles: 1) three or more forked poles and; 2) several straight poles. The forked poles have a two-stem fork at the top end. These three poles are interlocked so that they form a tripod. Upon this assembly of the forked poles, the straight poles are laid in a circular fashion. Reindeer hides were used as a cover until the mid-19th century when large amounts of inexpensive manufactured British textiles were made available to the Sami.

The traditional lavvus are still in use, but for ease of transportation modern designs have replaced the wooden poles with aluminum ones and heavier textiles with lighter fabrics. In addition, instead of an open fire an oven can be used. This reduces the smoke but produces less light making it quite dark inside. A lavvu of this type is easier to carry and is a common alternative to the tents often used for camping.

Very large lavvus also exist with enough room for dozens of people. These are typically used for large families.

The lavvu has been – and still is – a strong symbol for the Sami as a cultural haven. The lavvu played a prominent role in two events during the 20th century as more than just a shelter. The first was at the end of World War II during the winter of 1944/45 when the German troops retreated westward across northern Norway, burning most of the housing in Finnmark and eastern Troms counties before the Russian Red Army. Because of this destruction, many Sami lived in lavvus for many years afterward because of the lack of housing and unemployment from this period. Some of these Sami are still alive today who were born in these lavvus and have fond memories of them.