Cahill has emerged as quite possibly the Toffees' best player in the last couple of years and his transition to inspiring goalscorer has prompted Aussies to turn their attention to the fortunes of the Goodison Park outfit.
"He is Australia's David Beckham," Fargher said.
"He is on numerous adverts on the telly and on billboards all over the country, he has well and truly taken over from Harry Kewell as the nation's favourite player and is definitely converting Aussies to Everton.
"He always mentions Everton in his interviews and, as his personal fame has grown, so has knowledge of Everton among the younger generation, who previously were only interested in Liverpool, Man United, Arsenal and Chelsea."
And Everton captain Phil Neville said the club's pre-season trip down under was a success, partly due to Cahill's presence.
"We probably don't always get a clear idea of the adulation players like Tim have in their own countries and we saw that first hand when we went over there - I was proud to call him a teammate.
"But what we also saw was the popularity of Everton in Australia. The welcome we got there was absolutely terrific. We'd love to go back again at some point."