John Martin was a "labourer, carter, merchant, politician, runholder, land speculator".
Martin was born in Moneymore, County Londonderry, Ireland on 11 November 1822.
His family travelled to New Zealand on the Lady Nugent, eventually landing at Port Nicholson, on 17 March 1841. Martin was made a justice of the peace by William Fitzherbert in 1876, and in 1878 was called to the New Zealand Legislative Council by Premier George Grey. During his 14-year career in the Legislative Council, he only spoke four times, and came to be known as the "silent member".
He was to be a member of the Legislative Council from 25 July 1878 to 17 May 1892, when he died.