Mutual Building, Art Deco office building in City of Cape Town, South Africa

The Mutual Building is a 85-metre Art Deco tower clad in light tan stone panels, with a stepped ziggurat top and prismoid windows. Its central section has ten storeys above ground, with three basement parking levels and extra levels in the tower. The entrance hall has a 15-metre gold-leaf ceiling and black-and-gold marble, leading to the former banking hall with marble colonnades.

The South African Mutual Life Assurance Society, founded in Cape Town in 1845 by John Fairbairn, built this as its new head office in the 1930s, with construction finished in 1939 and a fanfare opening early in 1940. The Cape Times printed a 16-page supplement for the occasion. Standing 85 m tall, it was intended as the tallest building in South Africa. Old Mutual began moving staff to Mutual Park in Pinelands in the late 1950s; the last tenants left in May 2003, after which Louis Karol Architects converted it to flats.

The long carved stone frieze on the facade is by Ivan Mitford-Barberton, who worked with the Louw & Louw practice and Fred Glennie on the design. It depicts scenes from South African history, and scholars read it as expressing the colonial ideals of government promoted by Cecil Rhodes in the late nineteenth century. The building's name appears on the exterior as "Mutual Building" and in Afrikaans as "Mutual Gebou".

The building stands at the corner of Darling Street and Adderley Street in the central business district. Three basement levels provide parking for residents and visitors. The banking hall on the ground floor is accessible during business hours. The surrounding area offers numerous restaurants, shops and public transport connections. Most interior spaces remain closed to the public as they are used for residential purposes. Exterior viewing of the facade and frieze is possible at any time.

The banking hall preserves its 1939 furnishings with gold leaf ceilings, marble columns and carved wooden friezes. These elements document late 1930s craftsmanship and form one of the few completely preserved interiors from this era in Cape Town. The ceiling design shows geometric patterns characteristic of the period style. The combination of different materials illustrates the elaborate approach to designing representative business spaces of that time.