The Governor of Western Australia, Chris Dawson AC APM, will give a formal apology for the actions of his predecessor nearly 200 years ago, having been invited to the annual memorial gathering at the site of the Pinjarra Massacre on Tuesday.

October 28 this year marks the 191st anniversary of the day many Bindjareb Noongar people were shot and killed by an armed party of 25 men led by WA Governor Sir James Stirling in Pinjarra, in Western Australia's south west.

After an initial encounter on the banks of the river, the Bindjareb Noongar people fled into the river and were faced with Governor Stirling's party, who fired continuously at them for over one hour, killing multiple innocent victims.

For decades, colonial authorites misleadingly referred to the massacre as the 'Battle of Pinjarra', but the records make clear it was no battle.

Every year on this date, Traditional Owners, Elders and locals from Pinjarra gather to pay respect to those who died and to remember this crime. This year, the Governor was invited to attend the gathering and give an address; and will issue a formal apology for the actions of his predecessor in 1834.

The event will feature an exchange of trees as a symbol of ongoing reconciliation. The Governor will present an olive tree, propagated from the olive tree planted in the grounds of Government House by Governor Stirling around 1835.

In return, Traditional Owners will present him with a jarrah tree from Bindjareb Country, which will be planted in the grounds of Government House in Boorloo/Perth.

"I believe this action will be a significant step along the pathway to meaningful reconciliation," Governor Dawson said.

Medallions produced by the Perth Mint to mark the apology depict a Pinjarra tree, with the words karnadjil, wungening and boordiya. The reverse depicts the Government House Olive tree and the same three words in English: truth, healing and growth.