SJL Shannon


Diane Costigan

T 212.660.3903

Diane Costigan has more than 20 years of experience helping lawyers of all levels take ownership of, maximize and enjoy their careers. As Head of the Coaching Practice at SJL Shannon, she brings an integrative approach to her work with attorneys, coaching on a wide range of topics including business development, stress management, wellness, leadership and executive presence. In addition to her coaching work, Diane regularly helps law firms design and implement programs that empower their attorneys to reach peak performance.

Prior to joining SJL Shannon, Diane spent 10 years overseeing recruiting, legal personnel and professional development and training for a global Am Law 100 law firm. She speaks frequently at The National Association for Law Placement (NALP), The Professional Development Institute (PDI), The Professional Development Consortium (PDC) and The New York City Bar on career planning and strategy, profile building, mentoring and overall career and life wellness. She is also a prolific writer who has been published several times in The New York Law Journal and the National Law Journal. 

In 2016, Diane was named a PDC Trusted Advisor – an invitation-only program that encourages highly regarded legal professional development experts to share their knowledge and experiences with PDC members. Over the course of the next year, Diane will be focusing on deepening members' knowledge of the intersection between wellness and talent management. 

Diane earned her B.A., cum laude, Phi Beta Kappa, from the College of the Holy Cross and her M.A. in Organizational Psychology from Columbia University, Teachers College. She has a certificate in Organizational and Executive Coaching from NYU, is an Associate Certified Coach (ACC) with the International Coaching Federation and is a Certified Health Coach (CHC) through the Institute for Integrative Nutrition. She is currently pursuing certification in Emotional Freedom Technique (EFT/Meridian Tapping).

In her free time, Diane practices yoga and meditation and is a second degree black belt in karate. She lives in New York City with her husband and daughter (her proudest personal accomplishment).

Click here to download a PDF version of Diane's bio.


Diane's Coach Approach

Diane: In The Press + Insights