Artaxerxes I was king of Persia from 464 BC to 424 BC. He belonged to the Achaemenid dynasty and was the successor of Xerxes I. He is mentioned in two books of the Bible, Ezra and Nehemiah. He allowed the Jews to rebuild Jerusalem. He was followed on the throne by his son Xerxes II.

The name as given is the Greek form; the Persian form is Artakhshathra. He was later called Ardeshir.

After Persia had been defeated at Eurymedon, military action between Greece and Persia had come to a standstill. When Artaxerxes I took power, he began a new tradition of drawing off the Athenians by funding their enimies in Greece. This indirectly caused the Athenians to move the treasury of the Delian League from the island of Delos to the Athenian acropolis. This funding practice inevitably prompted renewed fighting in 450 B.C., where the Greeks attacked at the Battle of Cyprus. After Cimon's failure to attain much in this expedition, "The Peace of Callias" was agreed to between Athens, Argos and Persia in 449.

see also Artaxerxes II, History of Persia