Opened in 1880 with John Tyter as first postmaster. It was described as a red brick building with facings of Pyrmont stone; the style, modified Italian with deeply recessed arcades.
The clock and tower were under construction in 1886.

Kiama Post Office 1890's and 2008

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Kiama Buildings Post Office 1890s
Kiama Post Office Corner Closeup 2008

References:

Local Article

NSW Heritage