The Shanghai-Hong Kong Stock Connect will allow investors to trade across the border for the first time and is set to begin on 17 November.
It means global investors will now have access to Chinese stocks from Hong Kong, potentially resulting in $3.8bn (Â£2.3bn) worth of trades a day.
The system was expected to begin in October, but was delayed last month.
The tie up is seen as a key milestone in the capital market liberalisation of China - the world's second largest economy - where authorities keep a strong grip on the yuan currency.
Chinese regulators finally gave their approval on Monday.
The Hong Kong Monetary Authority, the territory's de-facto central bank, issued a statement saying it was "pleased" with the approval after "intensive discussions and preparations."
"The linking of the Hong Kong and Shanghai stock markets will also propel the development of offshore renminbi (yuan) business in Hong Kong to new heights," it said.
Regulators have approved a long-awaited plan to connect the Hong Kong and Shanghai stock exchanges.