Brian Underhill

Founder and CEO CoachSource LLC

Last Reviewed: September 18, 2026

Executive Summary

Brian O. Underhill is the Founder and Chief Executive Officer of CoachSource, an executive coaching firm built on a structural insight rather than on a personal practice. Most executive coaching is sold by individual coaches; CoachSource instead assembles, screens and manages a global bench, and sells large organisations a managed coaching programme across many leaders and many countries at once. The company describes its network as more than 1,200 professionals living or coaching in over 160 countries, admitted through a screen that it says roughly a quarter of applicants pass. Underhill is an organisational psychologist with a doctorate from the California School of Professional Psychology and a Professional Certified Coach credential from the International Coaching Federation. He learned the business running executive coaching operations for Marshall Goldsmith for about a decade before founding CoachSource, and he has since written and co-edited books that are standard references in the field, including Executive Coaching for Results and Mastering Executive Coaching.

Career Highlights

• Founded CoachSource and has led it as Chief Executive Officer since, building what the company describes as the world’s largest executive coaching provider.
• Grew the coach network to a figure the company currently states as more than 1,200 professionals across over 160 countries, with roughly 25 percent of applicants meeting its screening criteria.
• Spent approximately ten years managing executive coaching operations for Marshall Goldsmith before founding the firm.
• Co-authored Executive Coaching for Results, published by Berrett-Koehler in 2007.
• Co-edited Mastering Executive Coaching with Marshall Goldsmith and Jonathan Passmore, published by Routledge in 2019.
• Helped pioneer mini-surveys, a lightweight repeated-measurement method for tracking whether coaching actually changes leadership behaviour over time.
• Coaches and advises at organisations including Dell, Microsoft, Genentech and the State of California.
• Holds the Professional Certified Coach credential from the International Coaching Federation and keynotes on six continents.

Professional Journey

Underhill trained as a psychologist. He took a B.A. in psychology at the University of Southern California, then an M.S. and a Ph.D. in organisational psychology at the Los Angeles campus of the California School of Professional Psychology. That grounding shaped the distinguishing feature of his later work, which is an insistence that coaching outcomes be measured rather than asserted.

He spent roughly ten years at Marshall Goldsmith Coaching, managing the executive coaching operations of one of the field’s best-known practitioners. The role was operational rather than purely practice-based, and it exposed him to the problem that large employers face when they want coaching at scale: finding, vetting and coordinating coaches across business units, languages and countries is a logistics and quality-control problem that individual coaches are not set up to solve.

CoachSource was founded to solve that problem. Rather than selling Underhill’s own time, the firm recruits and screens a global network of coaches, matches them to client leaders, and manages the resulting programmes end to end for corporate clients. The company reports admitting only about a quarter of applying coaches, and its network now stands, on its own figures, at more than 1,200 professionals coaching in over 160 countries. Clients have included Dell, Microsoft, Genentech and the State of California. Underhill leads an executive team that includes a chief financial officer, a chief coaching officer, and senior leaders for client engagement and strategy.

Alongside the business, Underhill has been a persistent advocate for measurement in a field often criticised for the lack of it. He helped pioneer the use of mini-surveys, short repeated instruments administered to a leader’s colleagues to test whether coaching has produced durable behavioural change. He set out his approach in Executive Coaching for Results, published by Berrett-Koehler in 2007, and in 2019 co-edited Mastering Executive Coaching for Routledge with Marshall Goldsmith and Jonathan Passmore. He holds the Professional Certified Coach credential from the International Coaching Federation and speaks to leaders, HR managers and coaches on six continents.

Education

California School of Professional Psychology, Los Angeles

Doctor of Philosophy (Ph.D.), Organizational Psychology

California School of Professional Psychology, Los Angeles

Master of Science, Organizational Psychology

University of Southern California

Bachelor of Arts, Psychology