Plougonver gets its name from the Breton word “plu” meaning “parish”, and from a Celtic word “cunomaros”, translated as “Gonver”, the famous warrior.

It refers to the cruel Conomore or Comore, count of Poher, who murdered his wife
Triphine, and was father to Tremeur ou Treveur : Triphine means “small victory” whilst Tremeur means “great victory”.

The commune, overlooked as it is by the Menez Kersepers, has an undulating wooded appearance, and is watered by several streams. The most significant of these the Leguer, has its source at Penn-Leguer in Bourbriac. It used to provide the energy required by several mills which no longer exist.
There is one river which flows through the commune : the Leguer, while several streams feed into the Guic.

At 314 metres, Le Quenecador is the second highest point in the commune, whilst the lowest point is at Kergalaon at 180 metres.