Altbüron is a municipality in the district of Willisau in the canton of Lucerne in Switzerland.
Altbüron is first mentioned in 1194 as Alpurron.
Altbüron has an area, as of 2006, of 6.8 km2 (2.6 sq mi). Of this area, 60.6% is used for agricultural purposes, while 29.6% is forested. The rest of the land, (9.7%) is settled.In the 1997 land survey, 29.65% of the total land area was forested. Of the agricultural land, 57.82% is used for farming or pastures, while 2.8% is used for orchards or vine crops. Of the settled areas, 3.83% is covered with buildings, 0.44% is industrial, 1.77% is classed as special developments, 0.15% is parks or greenbelts and 3.54% is transportation infrastructure.
The municipality is located in the Rot river valley (Rottal).
Altbüron has a population (as of 31 December 2014) of 974.As of 2007, 81 or about 9.0% are not Swiss citizens. Over the last 10 years the population has grown at a rate of 5.7%. Most of the population (as of 2000) speaks German (93.8%), with Albanian being second most common ( 3.5%) and Serbo-Croatian being third ( 1.9%).