The administrative centre of the municipality is the town of Alta. was established on 1 January 1838. On 1 January 1863, the municipality was divided into two: Talvik to the north (population: 1,938) and Alta to the south (population: 2,442). On 1 January 1964, the two municipalities were merged back together to form the new, larger municipality of Alta. Prior to the merger, Alta had 6,629 residents and Talvik had 3,266 residents. The borders have not changed since that time.
The Rock carvings at Alta, dating from c. 4200 BC to 500 BC, are on the UNESCO list of World Heritage Sites. The Komsa culture was named after the Komsa mountain in Alta municipality, where the first archeological remains of this culture were discovered.
In the aftermath of the Sami Kautokeino rebellion of 1852, rebel leaders Mons Aslaksen Somby and Aslak Jacobsen Hætta were decapitated at Elvebakken in Alta, on 14 October 1854.
Their bodies were buried in graves just outside the Kåfjord Church graveyard in the village of Kåfjord in Alta, but their heads were sent on to the Anatomisk Institute at the Kong Medical Frederiks University in Oslo, where they were kept for more than a century as part of the university's skull collections. The two skulls were only relinqinished by the university in 1985, following a controversy and protests by Sami activists, and were in November 1997 buried at the Kåfjord Church in Alta, at the same spot as their bodies were buried over one hundred forty years earlier.
The town Alta was seriously destroyed by fire near the end of the World War II. It was rebuilt in subsequent years.
The Altasaken in 1979 made headlines for weeks, as many people, especially Sami people and environmentalists, demonstrated and used civil disobedience to prevent the building of a dam on the river Altaelva in order to produce hydropower. The dam was built, however, and the river still offers good salmon fishing. The king of Norway usually visits the river once in the summer to fish.
The urban area made up of Bossekop, Elvebakken, and Bukta, also known collectively as Alta became a town on 1 January 2000. The population has been growing steadily for many years.
For those interested in bird watching, the river outlet, known locally as Altaosen is well worth a visit. This tidal area is used as a stopover for many wetland species.