A 20-year-old member of the US Marines has been charged after assaulting a 60-year-old woman who works for the Australian Defence Force (ADF) at Gallipoli Barracks in Brisbane's north-west.

Police alleged the soldier attacked the woman while she was in her car in the Enoggera barracks carpark at 3.15pm on Tuesday.

Police said he also assaulted a police officer who tried to intervene in the altercation.

The woman was taken to hospital with non-life-threatening injuries and was later released.

The ADF said it was providing support to the woman.

"For privacy reasons, Defence will not provide further information on the condition of the staff member," the ADF said in a statement.

The Marine was charged with serious assault of a person over 60, assaulting a police officer and wilful damage.

Authorities have not revealed what the American soldier was doing at Gallipoli Barracks.

He is due to appear in court on July 18.