Intracellular parasites are microparasites that are capable of growing and reproducing inside the cells of a host. They are also called intracellular pathogens.

There are two main types of intracellular parasites: Facultative and Obligate.

Facultative intracellular parasites are capable of living and reproducing in or outside of host cells. Obligate intracellular parasites, on the other hand, need a host cell to live and reproduce. Many of these types of cells require specialized host types, and invasion of host cells occurs in different ways.

Facultative intracellular parasites are capable of living and reproducing either inside or outside cells.

Bacterial examples include:

Fungal examples include:

Obligate intracellular parasites cannot reproduce outside their host cell, meaning that the parasite's reproduction is entirely reliant on intracellular resources.

All viruses are obligate intracellular parasites.