Locoweed (also loco-weed, loco weed, and capitalizations and plurals thereof) may refer to:

Plants

• Species in the genera Astragalus and Oxytropis, collectively
• Species in the genera Astragalus and Oxytropis, that cause locoism (locoweed disease) in livestock
• Species with "locoweed" (etc.) in a common name, including:
• Astragalus alpinus, mountain locoweed
• Astragalus austiniae, ball-flowered locoweed
• Astragalus canadensis, Canada locoweed
• Astragalus coccineus, scarlet locoweed
• Astragalus didymocarpus, white dwarf locoweed
• Astragalus gambelianus, dwarf locoweed
• Astragalus holmgreniorum, Holmgren locoweed
• Astragalus lentiginosus, mottled locoweed, speckled locoweed, spotted locoweed
• Astragalus mollissimus, woolly locoweed, stemmed locoweed
• Astragalus oxyphysus, Diablo locoweed
• Astragalus pomonensis, Pomona locoweed
• Astragalus purshii, woolly-pod locoweed
• Astragalus speirocarpus, coilpod locoweed
• Astragalus trichopodus, coast locoweed, Southern California locoweed
• Astragalus whitneyii, Whitney's locoweed

• Cannabis, loco weed, when used as a recreational drug

• Datura stramonium, loco weed, when used as a hallucinogen

• Oxytropis arctica, arctic locoweed
• Oxytropis besseyi, Bessey's locoweed
• Oxytropis borealis, boreal locoweed
• Oxytropis campestris, Fassett's locoweed, field locoweed, northern yellow locoweed
• Oxytropis deflexa, nodding locoweed, pendant-pod locoweed
• Oxytropis huddelsonii, Huddelson's locoweed
• Oxytropis jordalii, Jordal's locoweed
• Oxytropis kobukensis, Kobuk locoweed
• Oxytropis kokrinensis, Kokrines locoweed
• Oxytropis lagopus, hare-foot locoweed
• Oxytropis lambertii, Colorado locoweed, Lambert locoweed, locoweed, purple locoweed, stemless locoweed, woolly locoweed
• Oxytropis maydelliana, Maydell's locoweed

• Oxytropis mertensiana, Mertens' locoweed

• Oxytropis monticola, late yellow locoweed, yellow-flower locoweed
• Oxytropis multiceps, southwestern locoweed
• Oxytropis nana, Wyoming locoweed
• Oxytropis nigrescens, black(ish) locoweed
• Oxytropis oreophila, mountain locoweed
• Oxytropis parryi, Parry's locoweed
• Oxytropis podocarpa, stalked-pod locoweed
• Oxytropis riparia, Ruby Valley locoweed
• Oxytropis scammaniana, Scamman's locoweed
• Oxytropis sericea, early yellow locoweed, locoweed, Rocky Mountain locoweed, silky locoweed, white locoweed, white point locoweed
• Oxytropis splendens, showy locoweed, whorled locoweed
• Oxytropis viscida, sticky locoweed

Music

• Loco Weed, Mel Tillis song