ANZ spokesman Pete Barnao confirmed there would be no job losses as a result of the move, with all 13 Queen St staff relocating to Lincoln Rd.
Mr Barnao said with more customers choosing to bank through other channels, such as online and mobile banking, it made sense to combine both branches.
"Customers tend to use branches for more detailed transactions or specialist advice, and that's a trend that all banks are seeing."
The decision to close the Queen St branch was "fairly recent" and had been made in the last few months, Mr Barnao said.
The new combined branch will have 41 staff after the move is completed.
Facilities at the Lincoln Rd branch would include a Smart ATM which accepts deposits, and customer Wi-Fi.
ANZ was confident there would be minimal inconvenience to customers, Mr Barnao said.
"Customers will still see the same familiar faces providing the same expert service they're used to."
The news follows the recent closure of several other Queen St businesses, including Shanton, which closed earlier this year when the company went into liquidation, and State Insurance, which closed almost all of its branches nationally late last year.
The Queen St branch was built on the site of the Centrepoint shopping centre, which was demolished in 1997.
