弓月蝴蝶鱼，俗名冬瓜蝶，为辐鳍鱼纲鲈形目蝴蝶鱼科的其中一种。

本鱼分布于中西太平洋，日本、菲律宾、**、泰国、马绍尔群岛、密克罗尼西亚、罗德豪岛、马里亚纳群岛、澳洲、新喀里多尼亚、帕劳、夏威夷群岛、斐济、东加、万纳杜、法属波里尼西亚包括等海域。

Not to be confused with the Red-tailed Butterflyfish (C. collare) and Chaetodon lunula (Raccoon Butterflyfish).

The Oval Butterflyfish, Red-finned Butterflyfish or redfin butterflyfish (Chaetodon lunulatus) is a species of butterflyfish (family Chaetodontidae). It is found in the Pacific Ocean from Eastern Indonesia to the Hawaiian islands. This is one species of a closely related group which includes the Blacktail butterflyfish which is found in the Red Sea and Gulf of Aden and the Melon butterflyfish which is found in the Indian Ocean.