A new city has been born in Western Australia, bringing a name change for the local council as well.

The Shire of Roebourne will now be known as the City of Karratha, encompassing Karratha, Dampier, Roebourne, Point Samson and Wickham.

The once-sleepy mining town of Karratha has been grown into a fully-fledged city, becoming eligible after its population reached 20,000.

Some locals say the change is meaningless unless it comes with better governance, lower rates and more facilities.

Residents have raised the lack of medical facilities, direct flights or a cinema as arguments that the city may be trying to punch above its weight.

But Karratha Mayor Peter Long has downplayed some for the local gripes, saying the benefits of changing status outweighed the negatives.

Mayor Long says that as a city, Karratha will attract new investment and opportunities for economic improvement.

He said it is beginning to pay off already, with the State Government's Pilbara Cities program (aimed specifically at boosting the populations of both Karratha and Port Hedland) bringing significant funding.

“We're getting a $200 million hospital,” Mayor Long told the ABC.

“We've just spent $65 million on the sporting complex - the Leisureplex.

“We're now in the design phase of our new cultural centre, new theatre and new library.

“I think we are ready for a city and we've got the population for a city, which we've actually had for many years already.”

Karratha Chamber of Commerce and Industry chief executive John Lally says that from a marketing perspective, City of Karratha is a more impactful name than the Shire of Roebourne