吴语，又称吴越语、江南話、江浙话，是汉语族的一种语言。主要通行于中国江苏南部（除南京和镇江的部分地区）、苏北启东海门通州和靖江的部分地区、上海、浙江大部分地区、安徽南部的部分地区、江西东北部和福建西北角及香港、美国旧金山等地说吴语的移民之间。从历史、文风、语言特性分析，吴语极近中古雅言，继承中古汉语的整齐八声调和三十六字母框架体系。
Wu (吴语) is a group of linguistically similar and historically related varieties of Chinese primarily spoken in Zhejiang province, the municipality of Shanghai, and southern Jiangsu province. This dialect group (Southern Wu in particular) is well-known among linguists and sinologists as being one of the most internally diverse among the Sinitic language groups, with very little mutual intelligibility among varieties within the dialect clusters. Wu dialects are typified linguistically as having preserved the voiced initials of Middle Chinese, having a majority of Middle Chinese tones undergo a register split, and preserving a checked tone typically terminating in a glottal stop.