About

About Sean Mannix

Sean M. Mannix is a law enforcement professional with 36 years of experience in public safety. He has served in various leadership roles, including Assistant Chief of Police in Austin and Chief of Police in Cedar Park, Texas. Throughout his career, he has focused on improving policing strategies, implementing advanced training programs, and promoting strong community leadership. After retiring in 2020, he served the public as the Statewide Traffic Incident Management Coordinator for the Texas Department of Transportation.

Childhood and Family

Retired Chief Sean Mannix was born in California and is one of five children. From a young age, Sean knew he wanted to work in law enforcement. His law enforcement officer father inspired him to follow a similar path. At 18, he joined the U.S. Marine Corps Reserve, which helped him develop leadership skills and a strong work ethic.

Educational Background

Sean holds a Bachelor of Science in Criminal Justice from Excelsior College, where he graduated with honors, and a Master of Arts in Homeland Security from American Military University. He is also a graduate of the FBI National Academy, the Leadership Command College, and the Senior Management Institute for Police. Additionally, Sean has completed the LAPD West Point Leadership Program.

Starting His Law Enforcement Career

Joining the Alameda Police Department

After completing his Marine Corps service, Sean returned to Alameda, California, and started his career in law enforcement. At 20, he became the youngest officer at the Alameda Police Department. He spent his early years learning the ropes of law enforcement, handling various patrol tasks, and responding to emergencies.

Moving to the Austin Police Department

In 1993, Sean moved to Austin, Texas, to continue his career in law enforcement. He joined the Austin Police Department, where he would work for the next 20 years. Sean quickly climbed the ranks, starting as a patrol officer and later taking on roles of greater responsibility. He became an Assistant Chief, overseeing several key divisions and projects within the department. Sean’s work in Austin included significant achievements such as reducing crime through the COMPSTAT model, enhancing community outreach programs, and promoting partnerships with federal agencies like the FBI and DEA.

Sean was a strong leader in Austin and was responsible for various essential tasks. He worked in multiple divisions, including the Organized Crime Division, which tackled significant crimes. He also worked in the Central Bureau, which handled crime prevention and community safety. 

Becoming Chief of Police

In 2013, Sean took on a new challenge when he became the Chief of Police for the Cedar Park Police Department. During his time as Chief, Sean focused on several key initiatives to set the department on a path to success. He worked to improve officers’ training programs, focusing on community policing, which emphasizes building positive relationships between law enforcement officers and the people they serve.

Retired Chief Sean Mannix also implemented innovative programs such as de-escalation training, body-worn cameras, and a nationally recognized wellness program for officers. Under his leadership, the department became one of the region’s most desirable workplaces, with a diverse workforce and strong community trust.

Recognition Across the Nation

During his time as Chief of Police, Sean gained recognition from national law enforcement organizations. The Cedar Park Police Department earned dual accreditation from the Texas Police Chiefs Association and the Commission on Accreditation for Law Enforcement Agencies (CALEA).

Under Sean’s leadership, Cedar Park also became known for participating in National Night Out. This event involves police departments connecting with their communities to build relationships and promote safety. Cedar Park was ranked first or second in Texas for National Night Out participation.

Retirement and Life After Law Enforcement

In 2020, after more than 30 years of service, Sean Mannix retired as Chief of Police in Cedar Park. Although retirement marked the end of his active law enforcement career, Sean remained involved in the field in other ways.

He continues to serve as a board member for Sigma Tactical Wellness, an organization dedicated to improving the health of first responders. His work with Sigma promotes cardiac health and wellness programs for police officers and other emergency responders. He also supports Williamson County Crime Stoppers, a nonprofit organization that solves crimes and improves public safety.

Beyond the Spotlight

Outside of his professional career, Retired Chief Sean Mannix is a loving family man. He has been married to his wife, Eileen, for many years, and they have four daughters: Nina, Katie, Haley, and Catalina. In September 2025, Sean and Eileen will celebrate their 20th wedding anniversary, marking two decades of love and support.

Sean is interested in aviation, fishing, and spending time outdoors. These hobbies allow him to relax and recharge after years of service in high-stress roles. Sean also loves reading and learning about new things. Whether it’s a book on law enforcement or a novel for pleasure, Sean believes constant learning is key to staying sharp and engaged in life.