Merriwa is a coastal, northern suburb of Perth, Western Australia, 36 kilometres (22 mi) north of the central business district.

[2] The original name survives in Hester Avenue, an east-west arterial road that forms the southern boundary of the suburb.

[3] Carnegie Private Estate was built in the mid 1990s in the area east of Connolly Drive by Town and Country Bank.

[4] In 1998, Merriwa was bifurcated along Connolly Drive by the City of Wanneroo, and the eastern half, including the Carnegie Estate, was gazetted as the new suburb of Ridgewood.

This development was also supported by a "Merriwa Structure Plan" devised by the City of Wanneroo, to provide adequate services and public open space for residents of the area.

The Merriwa Plaza, within the Quinns Beach Estate area, accommodates a large supermarket branch along with several other small shops and take-away restaurants.

Senior Merriwa students from Year 7 onwards fall into the Clarkson Community High School catchment area.

The staff and students of the college are expected to eventually move to a brand new, purpose-built facility in Alkimos in the future.[timeframe?

Hester Avenue on the southern edge of Merriwa also links directly to the Mitchell Freeway and Wanneroo Road in the east.

Lukin Drive runs along the northern boundary, which will connect to the Mitchell Freeway when the extension to Romeo Road is complete.

The road originally looped westwards onto Marmion Avenue, but was re-aligned during the development of the Seagrove Estate to exit north onto Lukin Drive instead.