Liberal leader Colin Barnett says he was taken aback by the decision to award Prince Philip a knighthood, saying the honours were usually for Australians.
Prime Minister Tony Abbott has been ridiculed on social media about the move, but dismisses the criticism as "kind of like electronic graffiti".
The West Australian premier said he didn't think the choice would embarrass the prime minister but admits he didn't expect it.
"I admit to being surprised," Mr Barnett told reporters.
"The Australian honours are generally for Australian citizens, however I don't think it's a big deal.
"Prince Philip over his life has been a great friend and supporter of Australia."
Mr Barnett added that being part of the Commonwealth had been one of Australia's great strengths, but he predicted it would eventually become a republic.
"Maybe some time in the next 10, 20 years there'll be another vote. The last time it was mucked up."
While a republican, Mr Barnett appears quite an admirer of the royals, naming Perth's new foreshore development after the Queen.
