William Addison Adamson (27 May 1858 – 10 June 1924) was an Australian politician.
He attended Brighton Grammar School and became a grain merchant.
From 1889 he worked as a stock and station agent, and he served on Brighton City Council from 1897 to 1913, with a term as mayor from 1901 to 1902.
In 1910, he was elected to the Victorian Legislative Council for South Eastern Province.
A Liberal, he was a minister without portfolio from 1913 to 1915 and Commissioner of Public Works from 1915 to 1917.