海带目（学名：Laminariales）是属于褐藻纲下的一个目。生长于海洋浅处的「森林」——海藻林之中。这种海藻林相信早在500万到2300万年前的中新世就已出现。它们的对海水的营养要求较高，温度介乎于6至14度左右是其最适生境。当中的两个属——巨藻属（Macrocystis）及腔囊藻属（Nereocystis），有极高的生长速度，一天可长近半米，最终可达致30至80米不等。此外也包括常用于食用的海带（Laminaria japonica）。

近年有研究把海带目的物种发展成为生物燃料的可能性。

Kelps are large seaweeds (algae) belonging to the brown algae (Phaeophyceae) in the order Laminariales. There are about 30 different genera.

Kelp grows in "underwater forests" (kelp forests) in shallow oceans, and is thought to have appeared in the Miocene, 23 to 5 million years ago. The organisms require nutrient-rich water with temperatures between 6 and 14 °C (43 and 57 °F). They are known for their high growth rate — the genera Macrocystis and Nereocystis can grow as fast as half a metre a day, ultimately reaching 30 to 80 metres (100 to 260 ft).