马更些河（英语：Mackenzie River，Deh-Cho），是一条北美洲的河流，也是北美洲第二大水系（总长4,241公里），仅次于密西西比河。马更些河发源于加拿大西北地区的大奴湖，将支流芬利河与皮斯河计算在内的话，马更些河也是加拿大境内最长的河流（总长1,738公里）。探险家当初以为河流流向太平洋，从而开通了横越北美的不结冰的西北水道，结果河流流入北冰洋，故最初名曰失望河（英语：Dissapointment River）。

马更些河流域面积为1,805,200平方公里（697,000平方英里），每秒的流量为10,700立方公尺（380,000立方英尺）。每年船只可航行时间约为5个月，河流从10月开始结冰，隔年5月解冻。

The Mackenzie River (Slavey language: Deh-Cho, big river or Inuvialuktun: Kuukpak, great river) is the largest and longest river system in Canada, and is exceeded only by the Mississippi River system in North America. It flows through a vast, isolated region of forest and tundra entirely within the country's Northwest Territories, although its many tributaries reach into four other Canadian provinces and territories. The river's mainstem runs 1,738 kilometres (1,080 mi) in a northerly direction to the Arctic Ocean, draining a vast area nearly the size of Indonesia. It is the largest river flowing into the Arctic from North America, and with its tributaries is one of the longest rivers in the world.