William James Mudie Larnach CMG (27 January 1833 – 12 October 1898) was a New Zealand businessman and politician.

For example his uncle Donald Larnach became a director of the Australian board of the Bank of New South Wales in 1846 and after his retirement to England became one of the leading financial authorities in the City of London.

[2] Larnach was also a family friend of William John Turner Clarke, said at that time to be the richest man in Australasia.

[4] He soon became quite prosperous, gathering large amounts of money through land speculation, farming investments, and a timber business.

[7] In 1877, at the behest of his South Island colleagues, he introduced a successful no-confidence motion against Harry Atkinson, the Premier of the day.

[8] He later undertook a long trip to England to arrange a government loan, although he also took advantage of the opportunity to launch a new business venture, the New Zealand Agricultural Company.

[1] With land prices falling and his timber company also suffering, Larnach's financial and personal position was declining.

He eventually became insolvent, although Larnach Castle and various other assets had been transferred to the ownership of his wife, Eliza, and were therefore spared.

The family mausoleum is the cemetery's most imposing structure, and is a miniature replica of Robert Lawson's First Church.