Forward Lake joins fellow Wales captain Jac Morgan in moving to Gloucester ahead of the new campaign, marking their first appearances playing in the Prem.
Former Gloucester captain Lewis Ludlow - who held the role for five years as the club's longest-serving skipper - spoke last month about losing the armband to Williams last summer, describing it as "brutal" and that he would take it back if offered.
Head coach George Skivington said that the decision was taken to wait until the team had spent a few weeks together before naming Williams' replacement.
"Dewi's leadership experience is there for everyone to see, and we're delighted he'll take on the role of captain this season," Skivington said.
"It was important for us to wait until the whole group had a few weeks in the building together under their belt before making a decision.
"The leadership process included input from the entire playing group, as well as our own assessment of who was best placed to lead this team forward through this season and beyond."
Extracted and lightly reformatted for readability. · Source: pt