Hollar earned a Bachelor of Arts from the University of Oklahoma in 1982 and a Juris Doctor from Georgetown University in 1989. He worked as a legislative assistant for former U.S. Rep. Mike Synar (D-Okla.) from 1983 until 1989. He moved to Montpelier in 1990. He and his wife, Jennifer Prescott Hollar, a fifth generation resident of Montpelier, have three sons.
A lawyer by profession, Hollar is a partner with Downs Rachlin Martin PLLC, Vermont's largest law firm. He is a registered lobbyist who has represented a wide range of clients in Vermont since 1990. Hollar previously served as the chair of the Montpelier school board from 2002-2010.
Hollar's predecessor, Mayor Mary Hooper, declined to seek re-election in 2012. Hollar was initially elected Mayor of Montpelier in the uncontested 2012 mayoral election on March 6, 2012. He was re-elected in 2014, defeating challenger Gwen Hallsmith by a margin of 66 to 34 percent.