Argishti I (Armenian: Արգիշտի, Argishti) was the sixth known king of the ancient Armenian kingdom of Urartu, reigning from 785 BC to 763 BC. He founded the citadel of Erebuni in 782 BC, which is the present capital of Armenia, Yerevan.
A son and the successor of Menua, he continued the series of conquests initiated by his predecessors. Victorious against Assyria, he conquered the northern part of Syria and made Urartu the most powerful state in the post-Hittite Near East. He also expanded his kingdom north to the Lake Sevan conquering much of Diauehi and the Ararat Valley. Argishtis built the Erebuni Fortress in 782 BC, and the fortress of Argishtikhinili in 776 BC.
Some linguists believe that the name Argištiše has Indo-European etymology (Armenian). Compare Armenian արեգ (translit. areg) – "sun deity", "sun".