Isaah Patrick Ferguson-Yeo is an Australian professional rugby league footballer who plays as a lock and second-row forward for the Penrith Panthers in the NRL and Australia at international level. He is widely regarded as one of the greatest locks in the game.

The Penrith Panthers are an Australian professional rugby league football club based in the Greater Western Sydney suburb of Penrith that competes in the National Rugby League (NRL). The team is based 55 km (34 mi) west of the centre of Sydney, at the foot of the Blue Mountains. Penrith are the current reigning NRL Premiers, having won the title five times, including the last three times consecutively.