Alfalfa pest, pests specifically linked to alfalfa by name, may be:

• Blue alfalfa aphid (Acyrthosiphon kondoi)
• Alfalfa bug (Piezodorus guildinii) a stink bug
• Alfalfa plant bug (Adelphocoris lineolatus)
• Alfalfa butterfly and alfalfa caterpillar (Colias eurytheme) a butterfly
• Alfalfa looper (Autographa californica) a moth
• Alfalfa moth (Cydia medicaginis) a moth
• Alfalfa leaf tier (Dichomeris acuminata) a moth that rolls alfalfa leaves
• Alfalfa webworm (Loxostege commixtalis) a moth
• Alfalfa webworm (Loxostege cereralis) a moth
• Alfalfa weevil (Hypera postica)

• Alfalfa cyst nematode (Heterodera medicaginis)
• Alfalfa dodder (Cuscuta approximata) a parasitic plant
• Large-seeded alfalfa dodder (Cuscuta campestris) a parasitic plant

• List of alfalfa diseases
• Alfalfa leafcutter bee (Megachile rotundata) which pollinates alfalfa