Bernard William (Catalan: Bernat Guillem; Occitan: Bernat Guilhem) (c. 11th cent.-1117) was the Count of Berga (as Bernard II, 1094-1117) and the Count of Cerdanya (1109-1117).

[1] A son of William I of Cerdanya and Sancha of Barcelona, he inherited Berga from his father in 1094.

In 1111, after the death of Bernard III of Besalú, he opposed the integration of Besalú into the County of Barcelona as it was technically a feudatory of Cerdanya, as were Fenollet and Vallespir.

However, he eventually agreed to abdicate these counties to his cousin and friend Raymond Berengar III of Barcelona.

When he himself died seven years later without heirs, Cerdanya passed to Barcelona.