John Hall Maxwell (1812–1866) was a Scottish agriculturist.
Maxwell, eldest son of William Maxwell of Dargavel, Renfrewshire, who died in 1847, by Mary, eldest daughter of John Campbell of Possil, near Glasgow, was born in Queen Street, Glasgow, in February 1812, and called to the Scottish bar in 1835.
He practised his profession until 1845, when he succeeded Sir Charles Gordon of Grimkin as secretary to the Highland Agricultural Society. At this time the number of members was 2,620, and the funds of the society amounted to 34,000l.; when he retired there were 4,200 members, and the finances had risen to 50,000l. The annual shows under his management displayed great improvements in the quantity and quality of stock, and in the workmanship of agricultural implements. He paid great attention to the collection of agricultural statistics respecting stock and crops, and for this and other services was, on 5 Feb. 1856, created a C.B. On his own estate at Dargavel he effected, at great expense, many improvements, especially in the reclamation of waste land. On 17 Jan. 1866 he was presented with one thousand guineas and a service of plate.
He died at his residence, Torr Hall, near Paisley, on 25 Aug. 1866. He married, 3 Aug. 1843, Eliza Anne Margaret, eldest daughter of Thomas Williams of Southwick Crescent, Hyde Park, London.