The gens Pactumeia was a minor plebeian family at ancient Rome.
Members of this gens are not mentioned by the historians until imperial times, when one branch of the family achieved high rank, holding several consulships during the first and second centuries.
The nomen Pactumeius belongs to a class of gentilicia formed from other names using the suffix -eius.
The closest known name seems to be the Oscan praenomen Paccius, occasionally written Pactius, which was itself used as a nomen gentilicium, as well as forming nomina with other suffixes, such as Pacilius, Paconius, and probably Pacidius.
This family was descended from a Publius Pactumeius, who evidently lived in Africa.