Denis O'Donnell (28 May 1875 - 16 June 1933) was a well-known entrepreneur in County Kerry, Ireland, in the early 1900s.
He was born in Tubrid, Ardfert, County Kerry, to Patrick O'Donnell of Tubridmore, and Bridget (née Griffin) of Lerrig. He was a grandson of John O'Donnell of Ardfert, who lived at Tubridmore, and descended from O'Donnells of Tyrconnell, following on the implantation of O'Donnells in Ardfert by Prince Hugh Roe O'Donnell en route to the Battle of Kinsale in 1601, as recorded in the Annals of the Kingdom of Ireland. He wrote poetry as a hobby. He initially farmed a family farm at Tubrid until he left to Ballyhaise, an agricultural college.
He married Hannah Leane, from Ballintobeenig, and they had one child, Patrick Denis O'Donnell. He died of an accident when his son Patrick was only 11 years old, and his widow, Hannah, subsequently emigrated to the United States of America at the outbreak of World War II, when their son, Patrick, joined the Irish Defence Forces.
Denis O'Donnell was schooled in Tubrid, in Spa, and later in Chapeltown national schools, and then farmed some years before proceeding to study and become one of the first graduates of Ballyhaise College, County Cavan, Ireland, with a Diploma in Dairy Science, having studied there from 1908 to 1910. This was the only such qualification available in the country at the time.
In his early career he was manager in some small creameries, one in County Tipperary, and others in Black Abbey, Adare, County Limerick; in Dicksgrove, Farranfore, and BallymcElligott, and Ballydwyer in County Kerry. He was influenced by the cooperative movement being driven by Sir Horace Plunkett, well described in the account of country life of the times by Elizabeth, Countess of Fingall, Seventy Years Young. Sir Horace Plunkett, MP, and later Senator of the Irish Free State, third son of Lord Dunsany, was father of the Irish agricultural co-operative movement, and founded the Irish Agricultural Organisation Society (now the Irish Co-operative Organisation Society), which included several hundred creameries. Accordingly, Denis O'Donnell actively organised farmers in the early cooperative movement in County Kerry, and founded the Lee Strand Co-operative Creamery on April 20, 1920 in Church Street, Tralee, still a going concern in 2009 although it relocated to Ballymullen in 1992. He owned a pub at #2 Edward Street, Tralee, run by his sister Bride, until her emigration to Kimberly, South Africa. The pub was sold in 1938. He also owned shops in Rock Street and Castle Street in Tralee. He was the first to introduce the pasteurisation of milk, much against the prejudice of dairy farmers at the time, and also was the first to market ice-cream in Tralee.