During historic times the island was inhabited by Ionians, who possibly came from Athens, as Thoukydidis records. Latin Plinius the senior preserved some of the names, the poets were calling the island. According to Myrtilos it was called Gavros and later Antandros. Kallimachos calls it Lasia, others Hydrousa and others Nonagriam and Epagrim (the last two meaningless words in greek). These names represent physical characteristics of the island, vegetation, water, etc.

Significant information about Andros during Geometric Time, comes from the discovery of an important settlement, rare for the time period, in the area of Zagora. The settlement flourished during 700-500 B.C. and, as it seems, vanished abruptly.

In Zagora were found 45 rectangular rooms with storage areas and yards, built with the andriotic all-time stone material, schist. Floors were covered with a layer of compressed mortar, as was common technique till recently. The layers of mortar at the roof were supported by wooden beams and schist plates.

An important building of the settlement was the later-built temple, which was probably dedicated for the worship of Goddess Athena.

During 7th century B.C. Andros was the metropolis of four important colonies in the areas of Chalkidiki and Strymon bay, in northern Greece. These were Akanthos, Sani, Stagiros and Argilos. According to Herodotus, during Persian Wars the Andriots, as well as the other islanders, seem to have been with the Persian side, offering "soil and water" to them.

The center during Classical Times, main city and information center to us, is the settlement, which was built at the present town of Paleopolis. The town seems to have been established around 700 B.C., when Zagora was abandoned. No systematic excavations have been made yet. Two findings by chance are very important, Hermes of Andros (Hellenistic copy) and the hymn to Goddess Isis, the latter still being used as a door lintel in a house in Paleopolis.

There was also an acropolis, port, agora (market) and sufficient fortification. About 60 silver and bronze coins have been found, many of which portray Dionysos, loved God in Andros.

During Peloponnesian War Andros lined up with its allies, Athenians, offering ships and soldiers. As a member of the Athenian Alliance, Andros was paying 72000 drachmas (12 talanta), as an island tax to the alliance fund.

In 411 B.C. Andriots broke away from Athens, lined up with Sparta, but came back and participated in the 2nd Athenian Alliance in 378 B.C.

After the battle in Haeronia in 338 B.C., where they fought allied with Athenians, the city-state of Andros came under Macedonian rule.

During Hellenistic historic period, which follows the death of Alexander the Great, Andros was under direct Macedonian control and participated in the islands community. Between 315 B.C. and 31 B.C., was consecutively under roman, macedonian, ptolemean and second macedonian, under Dimitrios, rule. In 199 B.C. roman and pergamean troops landed, seiged and captured Paleopolis. Andros was under Pergamos of Attalides till was given to the Romans. Important monument of hellenistic times is the Agios Petros Tower.