Spumaretrovirinae, commonly called spumaviruses (spuma, Latin for "foam") or foamyviruses, is a subfamily of the Retroviridae family.

[2] Spumaviruses are exogenous viruses that have specific morphology with prominent surface spikes.

The virions contain significant amounts of double-stranded full-length DNA, and assembly is rather unusual in these viruses.

Some spumaviruses, including the equine foamy virus (EFV), bud from the cytoplasmic membrane.

While spumaviruses will form characteristic large vacuoles in their host cells while in vitro, there is no disease association in vivo.