Harold "Hal" Orel was born in 1926 in Boston, Massachusetts. He served in the U.S. Navy during World War II as part of the Atlantic Fleet Camera Party, and went on to earn his BA in English at the University of New Hampshire in 1948. In 1949 he received his MA in English Language and Literature at the University of Michigan, followed by his PhD in English Language and Literature from the same university in 1952.

On completion of his PhD, Orel taught for four years in the English Department of the University of Maryland, including a year in their overseas program in Germany, Austria, and England. He then took up an associate professorship in the English Department of the University of Kansas (KU), earning the title of Distinguished Professor in 1975.

In addition to his teaching duties, Orel served as the Assistant Dean of Faculties in the Office of Research Administration from 1964 to 1967. During his time at KU, Orel published 30 books, of which he was either editor or author, and contributed numerous essays to encylopedias, anthologies, and academic journals. The majority of his monographs concern Thomas Hardy, but Orel wrote on a wide variety of other authors, including Sir Arthur Conan Doyle, Rudyard Kipling, Charles Darwin, and Rebecca West. Orel retired from KU in 1997, but remained an active scholar, publishing books and articles with regularity until shortly before his death in 2017.

Orel was active in a number of professional organizations and societies relating to his research interests, including the English and American branches of the Thomas Hardy Society, Modern Language Assocation (MLA), Royal Society of Literature, and American Committee on Irish Studies (now the American Conference for Irish Studies), of which he was a co-founder.

Orel also had a keen interest in technical writing and editing, working as a technical editor and consultant at the Applied Physics Laboratory in Silver Spring, MD and in the General Electric Aviation Jet Turbine Division in Cinncinnati, Ohio. After arriving in Kansas, he began work as a consultant at the Midwest Research Institute (MRI), giving training and seminars to staff on technical writing, with a particular emphasis on proposals and technical reports. He also gave guest lectures and seminars on technical writing to engineering students at KU.