The commune covers an area of 289 square kilometres and as at the 2013 Census had a population of 57,636 people.

[1][2] The term "Grand-Popo" is a European exonym for the ancient town and kingdom of "Hulagan" (Great Hula).

The Hula/Xwla/Phla people that once dominated the Togo-Benin coast traditionally regarded Great Hula as their ancestral town of common origin.

It may come from a generic Yoruba term "popo" for peoples to their "west", which was subsequently borrowed by the Portuguese to refer to the Hula/Phla specifically.

An alternative theory connects the "Popo" term to an ancient ruler called Kpokpo of Tado (an Aja town in the interior), which the Europeans may have confused with Hulagan.