The Port of Liverpool Building (formerly Mersey Docks and Harbour Board Offices, more commonly known as the 'Dock Office'), is a Grade II* listed building located at the Pier Head and along with the neighbouring Liver Building and Cunard Building is one of Liverpool's Three Graces, which line the city's waterfront. It is also part of Liverpool's UNESCO designated World Heritage Maritime Mercantile City.

The building was designed by Sir Arnold Thornley and F.B. Hobbs and was developed in collaboration with Briggs and Wolstenholme. It was constructed between 1904 and 1907, with a reinforced concrete frame that is clad in Portland Stone. The building acted as the headquarters of the MDHB for 87 years, from 1907 to 1994, when the company relocated to new premises at Seaforth Dock. In 2001, it was sold to Liverpool-based property developer Downing and between 2006 and 2009 underwent a major £10m restoration that has restored many features of the building to their original glory. Today, the building contains both residential and office space and is considered one of the most prestigious locations in the city.