Maia, Goddess of fertility and Spring
Mana Genita, goddess of infant mortality
Manes, the souls of the dead who came to be seen as household deities.
Mania, the consort of the underworld god Mantus
Mantus, a god of the dead
Mars, god of war and father of Romulus, the founder of Rome
Mater Matuta, goddess of dawn and childbirth, patroness of mariners.
Meditrina, goddess of healing
Mefitis or Mephitis, goddess and personification of poisonous gases and volcanic vapours.
Mellona or Mellonia, goddess of bees and beekeeping.
Mercury, messenger of the gods and bearer of souls to the underworld
Mena, Goddess of menstruation
Mens, Goddess of the mind and consciousness
Minerva, goddess of wisdom, war, the arts, industries and trades, and one of the Dii Consentes.
Mithras, god of soldiers, light, truth, and honor
Molae, daughters of Mars, probably goddesses of grinding of the grain.
Moneta, Titan goddess of memory, equivalent to the Greek Mnemosyne
Mors, god of death and equivalent of the Greek Thanatos.
Morta, minor goddess of death and one of the Parcae (Roman equivalent of the Moirai). The cutter of the thread of life, her Greek equivalent was Atropos.
Murcia or Murtia, goddess of sloth and laziness
Muta was the Goddess of silence
Mutunus Tutunus, a phallic god.