Lygaeus equestris, common name Black-and-Red-bug, is a species of ground bugs belonging to the family Lygaeidae, subfamily Lygaeinae.

These bugs can reach about 11 to 12 millimetres (0.43 to 0.47 in) in length. They have a characteristic red-black pattern, fully developed wings and long, powerful legs. The hemelytra have two transverse bands that reach the margin and a round white spot on the membrane. Scutellum is without bristles but with tiny hairs. The black band close to the eye is wider than the same. This species is very difficult to differentiate from Lygaeus simulans, that has a scutellum with long bristles, antennae with angulous tubercles and a larger red area on the head. The red-black pattern has a deterrent effect and serves to protect the insect (Mullerian mimicry or Batesian mimicry). By storing the toxic ingredients of their food plants, they are unpalatable to potential predators.

The nymphs and the imagos feed on juices of various plants, particularly milkweed (Vincetoxicum hirundinaria), Taraxacum species, Spring pheasant's eye (Adonis vernalis) and sometimes also on dandelions. Adults overwinter.

It is mainly present in Albania, Austria, Belgium, Bosnia, Bulgaria, Croatia, Czech Republic, Denmark, Finland, France, Germany, Gibraltar, Greece, Hungary, Italy, Montenegro, North Macedonia, Poland, Portugal, Romania, Russia, Serbia, Slovakia, Slovenia, Spain, Sweden and Switzerland. It inhabits lawns, forests clearings and scrubs, generally in warm calcareous areas.