Sir William John Brabazon, 2nd Baronet (16 September 1778 – 24 October 1840), was an Irish Member of Parliament.
Brabazon was born in County Mayo and educated at Trinity College, Dublin.[1]
He succeeded as second Baronet, of Newpark in County Mayo, on 3 July 1803. On 24 January 1835 he was elected one of the Members of Parliament for Mayo in the United Kingdom House of Commons, serving until 1840. On his death the baronetcy became extinct.