Fergal worked as the Déise senior hurlers’ physical coach from 2014 to 2018.
He takes over from Donal O’Rourke who stepped down after two successful years with the squad.
Last year Waterford reached the All-Ireland quarter-finals for the first time ever, and this year
they got to the same stage.
Fergal O'Brien told WLR Sport that the game is on a real high here in Waterford and it's down to the top class players who have played for the county in recent seasons.
He also paid tribute to Donal O'Rourke and his backroom staff for the work they carried out during the past two seasons.
Waterford picked up two camogie All Stars at Citywest in Dublin at the weekend.
Cappoquin's Lorraine Bray won her first award at wing back while championship top scorer Beth Carton from De La Salle collected her second at corner forward.
