LEROS is a family of chemical rocket engines manufactured by Moog ISP Westcott United Kingdom. LEROS engines have been used as primary apogee engines for telecommunications satellites such as the Lockheed Martin A2100  as well as deep space missions such as Juno.

Leros is a Greek island and municipality in the Dodecanese in the southern Aegean Sea. It lies (171 nautical miles) from Athens's port of Piraeus, from which it can be reached by an 11-hour ferry ride (or by a 45-minute flight from Athens). Leros is part of the Kalymnos regional unit. The island has been also called in and in .