咆勃爵士乐（英文：Bebop或Bop），又译波普、比波普、博普或、博普，源于美国，是一种兴起于40年代初中期的爵士乐演奏形式，相较于大乐团时期的爵士乐，咆勃爵士乐在垂直的和声上采用许多延伸音（Tension），水平的旋律构筑除与和声的延伸音相应外，也运用许多邻接音与半音来即兴。节奏运用许多重音错置手法造成特殊的律动。乐团编制较小为另一项特色，个人即兴能力与乐团的交互能力受到相当大的重视。此外，对音乐家来说演奏咆勃爵士乐的技巧难度也大幅提升，更需要高度的乐器控制能力才能演奏。

咆勃爵士乐奠定了现代爵士乐 的基础，其后于50年代发展的硬咆勃及酷派爵士都是基于咆勃爵士的延伸或反思。

Bebop or bop is a style of jazz developed in the early to mid-1940s in the United States, which features songs characterized by a fast tempo, complex chord progressions with rapid chord changes and numerous changes of key, instrumental virtuosity, and improvisation based on a combination of harmonic structure, the use of scales and occasional references to the melody. This style of jazz ultimately became synonymous with modern jazz, when both categories reached a certain final maturity in the 1960s.