大鼓 (英语：Bass Drum, 意大利语：Gran Cassa, 德语：Große Trommel)，泛指体积较大的双皮鼓。在西洋敲击乐器中较常使用。两边鼓面原来用动物皮革制作，近年已全改用塑胶或纤维鼓面。鼓桶原来用木制作，现在和定音鼓、小鼓一样，都改用较轻的合成纤维材料制造。

现时所指的大鼓，主要可分为三种：

A bass drum is a large drum that produces a note of low definite or indefinite pitch.

Bass drums are percussion instruments and vary in size and are used in several musical genres. Three major types of bass drums can be distinguished.