John R. "Jack" Pfeifer (1934-2009) was a prominent vascular surgeon and local leader in the Church of Jesus Christ of Latter-day Saints. Brother Pfeifer was born and raised in Saskatchewan. He earned his medical degree from the University of Saskatchewan. After doing his residency in Hawai'i, he practiced in Ontario before moving to Michigan where he had a private practice in Southfield and was a department head at Providence Hospital. From 2000-2007 Pfeifer was a professor at the medical school of the University of Michigan.