Plastid types in algae and protists include:
* Chloroplasts: found in green algae (plants) and other organisms that derived their genomes from green algae.
* Muroplasts: also known as cyanoplasts or cyanelles, the plastids of glaucophyte algae are similar to plant chloroplasts, excepting they have a peptidoglycan cell wall that is similar to that of bacteria.
* Rhodoplasts: the red plastids found in red algae, which allows them to photosynthesize down to marine depths of 268 m. The chloroplasts of plants differ from rhodoplasts in their ability to synthesize starch, which is stored in the form of granules within the plastids. In red algae, floridean starch is synthesized and stored outside the plastids in the cytosol.
* Secondary and tertiary plastids: from endosymbiosis of green algae and red algae.
* Leucoplast: in algae, the term  is used for all unpigmented plastids. Their function differs from the leucoplasts of plants.
* Apicoplast: the non-photosynthetic plastids of Apicomplexa derived from secondary endosymbiosis.
The plastid of photosynthetic Paulinella species is often referred to as the cyanelle or chromatophore, and is used in photosynthesis. It had a much more recent endosymbiotic event, in the range of 140–90 million years ago, which is the only other known primary endosymbiosis event of cyanobacteria.
Etioplasts, amyloplasts and chromoplasts are plant-specific and do not occur in algae. Plastids in algae and hornworts may also differ from plant plastids in that they contain pyrenoids.