Madison County Circuit Judge Andy Matoesian received 70 percent of the total vote to be retained to a sixth six-year term.
Matoesian, 72, received 52,017 yes votes to 21,341 no votes. He needed at least 60 percent to keep his seat.
Matoesian, who was first elected circuit judge in 1980, presides over major civil litigation.
In an open seat election, Madison County State's Attorney Bill Mudge ran unopposed to fill the vacancy of retiring Circuit Judge Daniel Stack.
Despite lack of opposition, Matoesian and Mudge raised $44,400 through the campaign committee Citizens for a Fair Judiciary. Most of the contributions came from local attorneys.
Mudge will be sworn in on Dec. 6.
"I'm honored and thankful for the trust voters have put in me," he said.
Mudge's legal career began after he graduated from St. Louis University School of Law in 1985. He has been an assistant state's attorney in Madison County and was in private practice with Lucco, Brown & Mudge beginning in 1987.
Most recently he served as state's attorney for two terms.
He said the transition from advocate to arbiter of facts and law will be "vastly different," but he was looking forward to the challenge and delivering his pledge to voters to be independent, fair and competent.
In a previous interview, Mudge said that his experiences in criminal law and on both the defendant's and plaintiff's side of civil law will greatly shape his time on the bench.
"It's given me some balance, helping me to understand human nature, which will help me in ferreting out the facts and applying the law to them," Mudge said. "I think if you're a big corporation or an individual coming into the court, you should get a fair shake."
Mudge said he would practice what he called "judicial economy," to ensure speedy and fair trials and to keep cases moving forward.
"Impartiality, fairness, promptness and decisiveness," Mudge has said. "I don't want litigants to be in limbo and not know what's going on. Letting the parties be heard promptly and making prompt decisions."
Chief Judge Ann Callis has said that Mudge would assume Stack's major civil case docket.
Until recently Stack has presided over the county's growing asbestos docket. Circuit Judge Barbara Crowder is now presiding over the asbestos docket.