Oltmannsiellopsis is a genus of marine colonial flagellate green algae[1] in the Oltmannsiellopsidaceae family of Chlorophyta.

[3] It was named in reference to the similar genus Oltmannsiella.

[1] It has three species, O. viridis, which forms four-celled colonies, O. unicellularis, which is single celled, and O. geminata, which forms two-celled colonies.

[1] In Japanese it is called ウミイカダモ (umiikadamo).

This Ulvophyceae-related article is a stub.