Amy C. Lannerd was born in Quincy, Illinois. In 1998, she received her B.S. degree in business administration from the University of Arizona and, in 2001, her J.D. degree from the University of Denver. In 2001, Judge Lannerd began her legal career as a general practitioner in Quincy. In 2008, she was approved as a family and divorce mediator.

The Illinois Supreme Court appointed her to the 8th Judicial Circuit Court in 2016, a position to which she was elected in 2018. As a circuit judge, she served on the committee to establish the Adams County Mental Health Court and as the alternate judge for the Mental Health and Drug Courts programs. In 2022, the Illinois Supreme Court assigned her to the Illinois Appellate Court for the Fourth District. Prior to her assignment, she presided over a felony docket since 2018.

Judge Lannerd has been a presenter multiple times at Ed Con, the mandatory biennial judicial education program for all Illinois judges. She has served as an Ed Con course supervisor and civil tract workgroup member. Prior to taking the bench, she presented at various Illinois State Bar Association continuing legal education courses. In addition, she has been a guest lecturer at Quincy University.

Judge Lannerd served as a member of the Supreme Court Pretrial Implementation Task Force Communications Subcommittee. She is a member of the Illinois Judges Association and Illinois State and Adams County Bar Associations.