Flower chafers are a group of scarab beetles comprising the subfamily Cetoniinae. Many species are diurnal and visit flowers for pollen and nectar or to browse on the petals. Some species also feed on fruit. The group is also called fruit and flower chafers, flower beetles, and flower scarabs. Around 4,000 species are known, but many of them are still undescribed.

Ten tribes currently are recognized: Cetoniini, Cremastocheilini, Diplognathini, Goliathini, Gymnetini, Phaedimini, Schizorhinini, Stenotarsiini, Taenioderini, and Xiphoscelidini. The former tribes Trichiini and Valgini were elevated in rank to subfamily. The tribe Gymnetini has the most species of the American tribes, and Goliathini contains the largest species and is mainly found in the rainforest regions of Africa.

Adult flower chafers are usually brightly coloured beetles, often metallic, and somewhat flattened in shape. The insertions of the antennae are visible from above, while the mandibles and labra are hidden by the clypeus. The elytra lack a narrow, membranous margin and are truncated to expose the pygidium. The abdominal spiracles are diverging so that several lie on the abdominal sternites with at least one exposed. The fore coxae are conical and produced ventrally, while the mid coxae are transverse or only slightly oblique. The mesothoracic epimera is visible from above. The tarsi are each equipped with a pair of simple (not forked) tarsal claws of subequal size.

A feature possessed by adults of many flower chafers, especially the Cetoniini, is lateral emmargination of the elytra.

Larvae are stout-bodied and very hairy with short legs. The head is partly covered by the prothorax. Each antenna has its apical segment as wide as the penultimate segment. The galea and lacinia are used to form a mala. The anal cleft is transverse. The mandible has a ventral stridulating area. The labrum is symmetrical with a deeply pigmented notch on each side of the midline.

Adult cetoniines are herbivorous, being found on flowers (from which they consume nectar and pollen), tree sap, and rotting fruit. Larvae generally live and feed in decaying plant matter (including decaying wood) or soil. In captivity, cetoniine larvae feed on soft fruit.

Many species in the tribe Cremastocheilini are known to be predaceous, feeding on hymenopteran larvae or soft-bodied nymphs of Auchenorrhyncha. Spilophorus species have been noted as feeding on the nesting material and excrement of South African passerine birds, while Spilophorus maculatus has been recorded feeding on Oxyrhachis tarandus nymphs and Hoplostomus fuligineus is known to feed on the brood of honey bees in South Africa and the pupae of the wasp Belonogaster petiolata. Campsiura javanica feeds on the larvae of Ropalidia montana in southern India. Cremastocheilus stathamae feeds on ants of the genus Myrmecocystus.

In terms of movement, adults are considered some of the best flyers among beetles. They can hover above and land on flowers or fruit. When threatened by predators, they escape by either performing a rush take-off or by falling toward the ground and then flying before impact. Many cetoniines fly with their elytra closed, as their hindwings can unfold and slide out under the elytra during flight (due to the emmargination of the elytra).