尼奈斯港（Nynäshamn）是瑞典的一座城市，2010年有人口2010人。

Nynäshamn is a locality and the seat of Nynäshamn Municipality, Stockholm County, Sweden with 13,510 inhabitants in 2010.

While interest in the area as a potentially useful port grew from the mid 19th Century, it was only with the opening of the railway to Stockholm in 1901 that Nynäshamn started to develop.