Piara Waters is a southeastern suburb of Perth, Western Australia within the City of Armadale. Previously part of Forrestdale and gazetted in 2007, Piara Waters is located approximately 20 kilometres (12 mi) south-southeast of Perth.

As a suburb that has been converted from small farms to residential lots, the population of Piara Waters has grown significantly from fewer than 100 in 2006 to over 14,000 as of 2021.^[2]

To accommodate this growth, new community and sporting facilities have been built. Piara Waters Primary School^[3] was opened in February 2012 (catering for students from Kindergarten to Year 6), and Piara Waters Senior High School^[4] began accepting students in early 2023. The school commenced with Year 7 students^[5] and will add each year to its growing cohort, until it reaches Year 12 in 2028.

In the latter half of 2023, the proposed Piara Waters Shopping Centre^[6] was opened to the public.

For the older community, a new residential lifestyle resort^[7] between Southampton Drive and Warton Road is currently populated with residents while ongoing development continues.

A large, central part of the suburb is taken up by the Piara Nature Reserve. This area was set on fire in March 2012 and threatened homes, but the fire was successfully contained by firefighters.

On 4 November 2023, a popular playground was destroyed when two 12 year old boys started a bushfire.^[8]