不等鞭毛门（学名：Heterokontophyta，又名Stramenopiles）是真核生物的主线，已知的下辖物种超过10万个品种，当中大多数属于藻类，从多细胞的大型藻类海带，到单细胞的各种浮游硅藻，这些藻类拥有多重内共生形成的多层膜叶绿体。其他值得注意的成员还有寄生性的卵菌纲，是不少植物性瘟疫的元凶，如爱尔兰马铃薯饥荒及近日的橡树突然死亡，都是由卵菌纲生物引起的。

不等鞭毛这一名称指的是在其生命周期的能动阶段，鞭毛虫细胞具有两种不同形状的鞭毛。

The heterokonts or stramenopiles (formally, Heterokonta or Stramenopiles) are a major line of eukaryotes currently containing more than 25,000 known species. Most are algae, ranging from the giant multicellular kelp to the unicellular diatoms, which are a primary component of plankton. Other notable members of the Stramenopiles include the (generally parasitic) oomycetes, including Phytophthora of Irish potato famine infamy and Pythium which causes seed rot and damping off.