Leptines (Ancient Greek: Λεπτίνης; died 375 BC) was a military leader from Syracuse, Sicily, Magna Graecia, active during his brother, Dionysius the Elder's wars.
He is first mentioned as commanding his brother's fleet at the Siege of Motya (397 BCE), and was for some time entrusted by Dionysius with overall command of the siege, while Dionysius was engaged in reducing the other towns still held by the Carthaginians.
However, having imprudently advanced with thirty of his best ships into the midst of the enemy, he was cut off from the rest of his fleet, and only able to escape by setting course to the open sea.
Many of their ships fell into the hands of the enemy with Leptines retreating with the rest of the fleet to Syracuse.
[1] Nothing more is recorded about Leptines until 390 BC, when he was again dispatched by Dionysius with a fleet to the assistance of the Lucanians against the Italian Greeks.
However, instead of joining them to crush their enemies, he gave refuge to the Thurian fugitives and succeeded in achieving peace between the contending parties.
For this conduct, which was entirely opposite to the views of Dionysius, he was deprived of the command of the fleet, which was given to his younger brother, Thearides.
After displaying the greatest personal prowess, Leptines fell in the action and the troops under his command immediately gave way.