Like the rest of the Canary Islands, Lanzarote is an entirely volcanic island, with numerous geological features resulting from recent volcanic episodes that have shaped much of its landscape. As the northernmost island of the archipelago, it forms part of a group that includes the smaller islets of La Graciosa, Alegranza, Montaña Clara, and Roque del Este and Roque del Oeste, collectively known as the Chinijo Archipelago.

Lanzarote is located between latitudes 29°25' (Punta Mosegos, Alegranza) and 18°50' (Punta de Papagayo) North, and between longitudes 13°20' (Roque del Este) and 14°57' (Punta Ginés) West. It covers an area of 862 km², and when including the 43 km² of the surrounding islets, the total area of the island and its islets is 905 km².

The island sits on the same geological platform as the neighboring island of Fuerteventura, with depths in the surrounding waters typically not exceeding one hundred meters. Lanzarote is also relatively close to the African coast, with Cape Juby lying approximately 140 km to the southeast.

Lanzarote's greatest longitudinal distance spans 58 km, while the transverse distance between two points on the same parallel measures 34.5 km. The island’s highest peak is the Peñas del Chache, which rises to 670 meters.

The island's coastline stretches for 213 km. In the geologically older areas, cliffs of considerable height can be found, while in more recent volcanic regions, the coastline is predominantly rocky, with smaller cliffs. The east and south coasts are home to several beaches, whereas the west coast is generally more rugged and steep, except for the famous Famara Beach.