On March 12, 1876, Trinkle was born in Wytheville, Wythe County, Virginia, as the youngest son of the prominent Trinkle family. After graduating from Hampden-Sydney College, he studied law at the University of Virginia and later opened a Wytheville law practice. Trinkle served as the chairman and an elector of the Democratic Party in 1916. He served two terms in the Virginia Senate before his election as governor. Trinkle also acted as a delegate for Virginia to the Democratic National Convention in 1924 and 1928. On November 25, 1939, he died in Richmond, Virginia and was interred in East End Cemetery in Wytheville. Trinkle Hall (formally known as Trinkle Library) on the campus of the University of Mary Washington and Trinkle Hall on the campus of the College of William and Mary are both named in his honor, as he helped secure funding to construct the buildings.