Isaac James MacCollum (August 18, 1889 – March 4, 1968) was an American physician and politician from Wyoming, in Kent County, Delaware.
He was a member of the Democratic Party, and served as the 11th Lieutenant Governor of Delaware.
He was elected Lieutenant Governor of Delaware in 1940, defeating Republican candidate Earle D. Willey of Dover, who was a Judge of the Court of Common Pleas.
In 1944 he ran for Governor against Bacon, but was defeated and returned to his medical practice full-time.
"[citation needed] Elections are held the first Tuesday after November 1.