Leonard Ingrams was the youngest of four sons. His parents were Leonard St Clair Ingrams and Victoria (née Reid). His mother was very musical and he started to learn the violin at the age of six. Later he played in the National Youth Orchestra under Sir Malcolm Sargent. He was educated at Stonyhurst College, where he was inspired by Peter Levi, and at Corpus Christi College, Oxford. He gained a double first in Classical Moderations and Greats. Subsequently he taught classics at Queen Mary College, University of London from 1965 to 1967.
In 1967 Leonard Ingrams joined Baring Brothers, a long-established merchant bank, where he was an international financier. After postings to Paris, Cologne and Hamburg, he was sent in 1972 to Saudi Arabia to head the Barings' team at the Saudi Arabian Monetary Agency (S.A.M.A). He subsequently left Barings and spent a six month sabbatical in Italy where he studied the viola under Bruno Giuranna in Siena. He then returned to Riyadh and worked independently as 'the greatest advisor' for S.A.M.A.. In the mid eighties he came back to England and was appointed a director at Flemings Bank. In the late nineties he returned to Arabia and worked in Bahrain. He subsequently set up his own investment consultancy, L.V.Ingrams & Co.
In 1982, Ingrams bought Garsington Manor on the edge of the village of Garsington east of Oxford, England. He later became well known for founding Garsington Opera in 1989, an annual season of opera in the manor gardens, designed by Lady Ottoline Morrell during the First World War. Under his musical directorship the opera company became known for world class productions. Ingrams would travel extensively to seek out singers for particular roles, and under his leadership the Garsington Opera orchestra was established, with its core from the Guildhall Strings.
Ingrams married Rosalind Moore in 1964. He died after a heart attack at the age of 63 in 2005, while driving home from a performance of Verdi's Otello at Glyndebourne. They have a son and three daughters. Ingrams also has a surviving elder brother, Richard Ingrams, one of the founders of the satirical magazine Private Eye.