波兹南（波兰语：Poznań，官方全名：波兹南首府城市；拉丁语：Posnania；德语:Posen，中译为波森；意第绪语：פּױזן Poyzn）是波兰中西部的一个城市，人口578,900人（2002年），是波兰第五大城市。该市位于瓦尔塔河沿岸，是波兰最古老的城市之一，也是该国重要的历史中心。是河港城市。波兹南圣伯多禄圣保禄圣殿总主教座堂是波兰最早的一座主教座堂，堂内有波兰早期统治者的墓穴：梅什科一世大公、国王波列斯瓦夫一世、国王梅什科二世、卡西米尔一世大公、大波兰普热梅斯瓦夫一世大公及国王普热梅斯瓦夫二世。波兹南参加过汉萨同盟。波兹南被卷入过三十年战争和大北方战争。在第二次瓜分波兰后被划入普鲁士。一战结束前曾是普鲁士王国和德意志帝国波森省的首府，战后割予波兰，改名波兹南。二战期间，德**队和苏联军队在这里展开激烈战斗。城市的55%在战争中被毁。在战后城市得到了修复。战后这里发生过大规模反苏示威。波兰民主化之后，波兹南是大波兰省的省会。

Poznań ([ˈpɔznaɲ]; German:Posen, known also by other historical names) is a city on the Warta river in west-central Poland, in Greater Poland region. It is best known for its renaissance old town, destroyed during World War II and then rebuilt, and Ostrów Tumski cathedral. After the second partition of Poland Poznań was administrated by Prussia, and then, with the unification of Germany after the Franco-Prussian War of 1871, the province of Posen became part of the German Empire. Furthermore, the city of Posen was officially named an imperial residence city, leading to the construction of the Imperial Castle, the Imperial District, the Opera House, new city walls, railway station and many other sites which make a big part of its landmarks to this day. Today, Poznań is an important cultural and business centre and one of Poland's most populous regions with many regional customs such as Jarmark Świętojański, traditional Saint Martin's croissants and a local dialect.