Lewis Linn McArthur was born in 1917 in Portland, Oregon. He studied economics at the University of California at Berkeley, and served in the U.S. Army in the Aleutian Islands during World War II. After the war, he worked for 40 years as an industrial engineer for the Ray F. Becker Company.

McArthur's father, Lewis A. McArthur, was the author of Oregon Geographic Names in 1928. Though Lewis L. McArthur was not formally trained as a historian, he was most well known for continuing his father's work in studying and compiling the history of place names in Oregon. He served on the Oregon Geographic Names Board from 1958 to 2006, and between 1974 and 2003, he published the fourth, fifth, sixth, and seventh editions of Oregon Geographic Names. McArthur also served on the state historic preservation committee and the Historic Columbia River Highway State Advisory Committee.

McArthur and Joyce Abigail Clark of Eugene, Oregon, married in 1946. The couple had four children: Lewis, Mary, Sarah, and Susan. Lewis L. McArthur died in 2018 at the age of 101.