Loomis grew up in Eugene, Oregon and graduated from Willamette High School in 1974, then attended Northwest Christian University in Eugene, where he played basketball. He earned his degree in accounting from the University of Oregon and a masters degree in sports administration from Wichita State University. Before coming to the Saints, Loomis spent 15 years in the Seattle Seahawks organization. Loomis joined the Saints in 2000 and became general manager in 2002. He was with the Saints when they were forced to relocate to San Antonio in the wake of Hurricane Katrina, and helped rebuild the team afterward, culminating in its victory in Super Bowl XLIV.