Catlett attended Missouri State University, where he earned a Bachelor of Arts degree before continuing his legal education at Saint Louis University School of Law. After receiving his Juris Doctor, he was admitted to the Missouri Bar in 1996. He later became licensed to practice law in Illinois and Kansas in 1997, giving him the ability to represent clients across three states. He is also admitted to practice before the United States District Courts for the Eastern District of Missouri, Western District of Missouri, and Southern District of Illinois.

While attending law school, Catlett gained practical courtroom experience as a law clerk for the City of St. Louis Circuit Attorney’s Office in 1993. He later joined the law firm Diekemper, Hammond, Shinners, Turcotte & Larrew, P.C., where he worked as a law clerk from 1994 to 1996 before becoming an associate attorney from 1996 to 1997.

In 1997, Catlett founded William Catlett, LLC in St. Louis. Since then, he has operated as a sole practitioner, providing legal services to individuals, families, property owners, and businesses throughout the region. Over the years, his practice has expanded to include multiple areas of law, allowing him to help clients facing legal issues that often overlap between family, financial, and property matters.

Family law has remained one of the primary areas of his practice. He represents clients in divorce, paternity, child custody, child support, adoption, juvenile law, orders of protection, and prenuptial agreement matters. He works to resolve disputes efficiently while helping clients understand the legal process and the long-term effects of court decisions involving their families.

Bankruptcy law has also been a significant part of his career. Catlett represents both debtors and creditors in bankruptcy proceedings. He works with individuals seeking financial relief through Chapter 7 or Chapter 13 bankruptcy and advises clients on asset protection strategies when bankruptcy may not be the best option. He also represents creditors seeking relief from the automatic stay when appropriate.

Another major area of Catlett’s practice involves probate, guardianships, and mental health law. He has been appointed in approximately one hundred involuntary commitment hearings each year and around thirty guardianship hearings annually. He also handles probate administration and estate matters, helping families manage legal responsibilities following the death or incapacity of a loved one.

Since 2015, Catlett has served as a court-appointed guardian through the St. Louis City Probate Court. His work in guardianship cases involves protecting the interests of individuals who are unable to manage their personal or financial affairs independently. These matters often require coordination with families, healthcare professionals, and the court system.

In 2017, Catlett became a Forensic Science Trainer of Physicians for Saint Louis University. In this role, he prepares resident physicians to provide effective courtroom testimony during legal proceedings. His experience in both litigation and healthcare-related legal matters has allowed him to help medical professionals better understand the legal process and their responsibilities as witnesses.

Catlett also represents clients in criminal defense matters, particularly driving while intoxicated cases. In addition, he has experience handling real estate disputes, wills and trusts, powers of attorney, probate administration, and guardianship proceedings. Earlier in his career, he was licensed as a title agent in Missouri and held real estate broker licenses in both Missouri and Illinois for more than twenty-five years.

Throughout his career, Catlett has emphasized communication and transparency. He believes clients should understand the legal process, the options available to them, and the likely outcomes of their cases. He is known for explaining legal concepts in straightforward language so clients can make informed decisions without unnecessary confusion.

Catlett has also said that his work is guided by fiduciary responsibility. He believes an attorney’s role is to place the client’s interests first while pursuing practical, efficient, and cost-effective solutions. Whether representing someone in a family law dispute, bankruptcy case, guardianship proceeding, criminal matter, or probate issue, his goal is to help clients navigate the legal system with confidence and a clear understanding of their options.

Today, William Catlett continues to practice law in St. Louis through William Catlett, LLC. His practice reflects more than thirty years of courtroom experience, service across multiple areas of law, and a continued commitment to helping clients resolve complex legal matters with honesty, clarity, and professionalism.