The ending in "a" (La Rocca) suggests a toponymic origin for an ancestor coming from a place called Rocca, in a period when surnames were formed (from 15th century onwards). At first it might have been "della Rocca" then shortened to Larocca. In this province there is a Roccanova, but other places are possible.
An origin from the Rocco name would not use the article "la".
Origin of the name LaRocco and St Rocco
Posted by Molly Larocco on October 05, 2011 at 20:34:12:
I am wondering if anyone knows about the origin of the name La Rocco/a. Was it changed from an "a" ending to an "o" ending in the US? Why? Is there any connection to St Rocco? What, if any is the connection to St Rocco and Potenza?