Polemonium occidentale is a species of flowering plant in the phlox family known by the common names western polemonium and western Jacob's-ladder. There are two subspecies. The common ssp. occidentale is native to western North America from British Columbia to Colorado to California, where it can be found in moist areas of many habitat types, including meadows and woodlands. There is also a rare subspecies, ssp. lacustre, which is known only from a total of three counties in Minnesota and Wisconsin, and is found only in white cedar swamp habitat there.