The man, in his mid-thirties, was lightly wounded to the head and taken for medical care, a police spokeswoman said. He was detained and was facing potential charges of disrupting the public order.
Police also detained the four men suspected of assaulting the tourist, identified as residents of Israeli-annexed east Jerusalem.
The spokeswoman said it was an isolated incident and there was no further violence at the mosque compound, the third holiest site in Islam and the holiest for Jews, who refer to it as the Temple Mount.
The mosque compound sees frequent clashes between police and Palestinians, at times over Jewish visits that are perceived as an attempt to gain full control over the site, currently under Jordanian custodianship.
Non-Muslims are allowed to visit the compound, but Jews are forbidden from praying or displaying national symbols for fear of triggering tensions with Muslim worshippers.