He was born in
Edinburgh in 1768. His father held a post in the printworks of
Alexander Kincaid,
Lord Provost of Edinburgh in 1776, and Kincaid was named in his honour. It is thought his father died young as his mother "Mrs Mackenzie" is noted as a merchant trading from the
Luckenbooths, next to
St Giles Cathedral in 1773. By 1800 he was trading as a wine merchant in his own right, from the "head of James Court" on the
Lawnmarket. He later became a partner in William Hall & Co, wine merchants on the
Lawnmarket in Edinburgh. In 1806 he was living at Buchanan Court in Edinburgh's Old Town. He moved to a new house on Gayfield Square as soon as it was built (c.1808). He joined the Town Council and in 1810 a public (but anonymous) letter was sent to "Bailie Kincaid Mackenzie" accusing the Edinburgh Town Council of various financial improprieties. In 1818, during his period as Lord Provost, a similar accusation caused him to publish the council's finances in full. In 1819, at his house on the west side of Gayfield Square, he hosted a visit from
Prince Leopold of Belgium, and this name was then used for the mew buildings under construction nearby, at the junction of
Leith Walk and London Road, still known as Leopold Place. He was noted in 1819 as an ex-President of the Edinburgh
Magdalene Asylum for Fallen Women. He became Treasurer of
George Heriot's Hospital in 1822/23 in place of James Denholme at a salary of £500 per annum. He died during dinner at his home, 5 Gayfield Square at the top of
Leith Walk on 2 June 1830 aged 62. He rose suddenly saying that he felt unwell and expired before he reached the diningroom door. He is buried on the central western terrace of
New Calton Burial Ground in Edinburgh, facing south to
Arthur's Seat, next to the grave of Sir
Robert Christison. ==Family==