The department announced on Thursday that it has sanctioned Tobaiwa Mudede, a well-known and prominent supporter of President Robert Mugabe.
As registrar-general, Mudede controls the roll of voters that is widely alleged to be used by Mugabe's ruling party to rig elections.
The department says Mudede oversaw critical elements of Zimbabwe's flawed July 2013 presidential and parliamentary elections.
An Angolan businessman, an attorney from Singapore and a business based in Zimbabwe also were sanctioned for allegedly undercutting democracy or facilitating public corruption.
The sanctions freeze assets they hold within US jurisdiction and prohibit US citizens from doing business with them.