Perth will have a chance to unite as one to watch the world's biggest sport events on the edge of the Swan River after a new giant TV was erected outside Optus Stadium.

The142sqm LED screen in the BHP Amphitheatre outside the $1.8 billion stadium will live-stream its first event on Saturday night when Perth hosts its first Bledisloe Cup match between the Wallabies and All Blacks, with fans unable to source a ticket to the sell-out sure to take advantage.

The big screen is unveiled outside Optus Stadium ahead of Saturday's Bledisloe Cup clash. Credit:Frizz Ferguson

The state government also revealed on Wednesday that AFL fixtures featuring West Coast and Fremantle would be streamed live on the $2.4 million screen from this Sunday, when the Eagles play Adelaide at 2.40pm.

The amphitheatre can house 1000 people on its grassed slope and the government said it was likely to be licensed from next year for entertainment such as outdoor movies and community events.