Authorities in Sydney's western suburbs are seeking public assistance to locate a missing 13-year-old Indigenous girl.

Shaya Baig was last seen at a school on North Parade in Rooty Hill around 2pm on Monday, May 13.

Concerns for her welfare escalated after she failed to be located or contacted, prompting her reported disappearance to officials from the Mt Druitt Police Area Command, who initiated investigations to find her.

Shaya is described as of Aboriginal/Torres Strait Islander descent, of a medium build, standing approximately 170cm tall, and has brown hair and brown eyes.

She was last sighted wearing a school uniform featuring a navy top and pants, and carrying a black backpack.

Known to frequent areas including Mt Druitt, Plumpton, Blacktown, and the Sydney CBD, her absence has sparked concern among both law enforcement and family members due to her age.

Members of the public possessing information regarding Shaya's whereabouts or potential sightings are urged to promptly contact the Mt Druitt Police Area Command or Crime Stoppers on 1800 333 000.

Information is treated in strict confidence.

The public is reminded not to report information via NSW Police social media pages.