塞纳河（Seine）是流经巴黎市中心的法国第二大河，全长780公里，流域面积7.8万平方公里。

塞纳河主流源头位于勃艮第地区，科多尔省的首府第戎西北30公里的朗格勒高原，流经奥布省的首府特鲁瓦，穿过巴黎市中心，经过诺曼底的鲁昂，到达勒阿弗尔入海，流入拉芒什海峡（英语称为英吉利海峡）。

北部支流有马恩河、瓦兹河、奥布河；南部支流有约纳河、厄尔河。通过17世纪-18世纪修建的运河，可以沟通莱茵河的支流默兹河，法国南部主要河流罗讷河的支流索恩河，以及法国第一大河卢瓦尔河，吃水浅的船只可以直接航行到比利时、德国和地中海。上游马恩河和奥布河流域是香槟酒的主要产区。

The Seine (/seɪn/ SAYN; French:La Seine, pronounced: [la sɛːn]) is a 777-kilometre (483 mi) long river and an important commercial waterway within the Paris Basin in the north of France. It rises at Source-Seine, 30 kilometres (19 mi) northwest of Dijon in northeastern France in the Langres plateau, flowing through Paris and into the English Channel at Le Havre (and Honfleur on the left bank). It is navigable by ocean-going vessels as far as Rouen, 120 kilometres (75 mi) from the sea. Over 60 percent of its length, as far as Burgundy, is negotiable by commercial riverboats and nearly its whole length is available for recreational boating; excursion boats offer sightseeing tours of the Rive Droite and Rive Gauche within the city of Paris.