The last ferry in a new Sydney Harbour fleet will be christened Ferry McFerryface - the Australian city's second favourite choice after the now famous jokey Mc-moniker, Boaty McBoatface.

New South Wales state government officials overruled the most popular name for the ferry after the trendsetter was first snubbed last year as a name for a British polar survey vessel.

That ship was christened Sir David Attenborough in honour of the naturalist and broadcaster and Boaty McBoatface became the name of one of its remotely operated submarines.

"Given ’Boaty’ was already taken by another vessel, we’ve gone with the next most popular name nominated by Sydneysiders," New South Wales Minister for Transport and Infrastructure Andrew Constance said in a statement on Tuesday.

"Ferry McFerryface will be the harbor’s newest icon and I hope it brings a smile to the faces of visitors and locals alike," he added.