Cleeve, Sir Thomas Henry (1844–1908), industrialist, was born 5 June 1844 in Richmond, Quebec, Canada, eldest son among six sons and one daughter of Edward Elms Cleeve (1814–85), originally of Woolwich, England, and later of Cleveland, Quebec, and his wife Sophia Olivia (d. 1904), daughter of Edward Journeaux, JP, of Melbourne, Quebec, formerly of Dublin. Educated in Canada, Cleeve and his brother Frederick Charles arrived in Limerick in 1864 to work at J. P. Evans & Co, a firm of general merchants based in Thomas St. and owned by their mother's brother, Ben Journeaux. On the death of his uncle, Cleeve took over the firm and began bailing hay to supply to the local military garrison; during the Zulu war (1879) he won a valuable contract to supply hay to the army. J. P. Evans & Co. expanded to premises in George's St., selling agricultural tools and seeds. In 1881 Cleeve established a factory for manufacturing prepared coffee at the Old Shipyard in the Lansdowne area of Limerick. In the same year he wrote a pamphlet setting out his vision for the future of milk production and condensed milk in Ireland. At the time most dairy production was carried out on individual farms, but Cleeve believed that the future lay in centralised production, backed up by a network of creameries to which farmers would deliver their milk.
Three years after publishing his pamphlet and attempting to persuade Munster farmers that his ideas would benefit them, Cleeve began producing condensed milk and butter on a small scale. In 1889 he purchased the premises adjoining his enterprise at Lansdowne and established the Condensed Milk Co. of Ireland with Edmond Russell, a miller, and a solicitor named Beauchamp. As the business grew, three more brothers arrived from Canada and each took responsibility for a division of the Cleeve enterprises. The business grew rapidly and by 1892 was using the milk of more than 10,000 cows to produce large quantities of butter for the home and export markets and 60,000 tins of condensed milk a day. By this time Cleeve had also established offices at London and Liverpool. By 1898 the Cleeve business in Munster consisted of a network of creameries and nineteen factories (including the headquarters at Lansdowne with its famous red brick chimney). Together these concerns employed nearly 2,000 people and consumed 350,000 gallons of milk a week, supplied by 25,000 cows. In addition to this Cleeve's produced its own tins for the condensed milk business, which used 100,000 tins every day for the home and export markets.
Thomas Henry's position within Limerick industry led to his appointment to the harbour board and the chamber of commerce, on which he served as president. Strongly unionist, he was elected a city councillor (1899–1902) following the passing of the local government act of 1898. In addition to being a JP (1892) Cleeve was high sheriff of Limerick city (1899–1901, 1908) and DL (1905). On the occasion of Queen Victoria's visit in April 1900 he arranged for 500 employees to travel to Dublin by special train. After the royal visit Cleeve was knighted for his services to industry.
By the time he died, Thomas Henry Cleeve had created an enormous business that consisted of three companies: the Condensed Milk Co. of Ireland, which produced butter, condensed milk, cocoa, chocolate, caramel, and sweets; Cleeve Brothers, which distributed the dairy products; and J. P. Evans & Co., which supplied agricultural machinery and dairy engineering services. He also owned the Cleeve Canning & Cold Storage Co. at Westminster, British Columbia. He died 19 December 1908 in Limerick and was buried in the family vault at St Mary's cathedral.
He married (1874) Phoebe Agnes (d. 10 November 1933), daughter of Jonathan Dann of Fermoy, Co. Cork. They had two sons and three daughters and lived at Sunville, North Circular Road, Limerick.