  The nearby, young, extinction-free {\sigma} Orionis cluster is acknowledged
as a cornerstone for studying the stellar and substellar formation and
evolution, especially at very low masses. However, the relatively limited
knowledge of multiplicity in the cluster is dispersed among numerous papers and
proceedings with very different aims and, therefore, is difficult to apprehend
even for researchers in the subject. Here, I review comprehensively the
sexdecuple system {\sigma} Ori in the central arcminute, and all close (rho =
0.4-4 arcsec) and wide (rho > 4 arcsec) binaries, triples, hierarchical
multiples, and spectroscopic binaries in the cluster that have been reported in
the literature until 2014. I conclude with a brief enumeratation of the next
steps that should be taken in the near future for having a clear picture of the
multiplicity in the {\sigma} Orionis cluster.
