Lampsacus, an ancient Greek city of Mysia in Asia Minor, situated on the Hellespont near where it expands into the Propontis. Its original name was Pityusa, but it was colonized at an early period by Ionians from Phocaea and Miletus, who called the place Lampsacus. It had an excellent harbor, and acquired extensive commerce. Miltiades, son of Cypselus, who had established himself in the Thracian Chersonese, made war on the Lampsacenes, but was surprised and taken prisoner by them. Crcesus espousing his cause, they restored him to freedom. After the rise of the Persian power, Lampsacus became subject to it. On the overthrow of the Persians at Mycale (479 B. C), Lampsacus joined the Athenian confederacy, but it revolted when intelligence arrived of the destruction of the Athenian armament and army in Sicily (413). It was reduced by Strombichides, and remained dependent on Athens till the time of Alexander, when it was absorbed in the Macedonian, and subsequently in the Roman dominions. In the age of Stra-bo it was still a place of importance. Charon the historian, Anaximenes the rhetorician, and Metrodorus the philosopher, were natives of Lampsacus, which was also a chief seat of the worship of Priapus. Its territory was famous for wine.

The name of Lampsacus is still preserved in that of Lapsaki, a small village 5 m. S. of Gallipoli, near the probable site of the ancient city, of which no trace now remains.