William Bridges (1933 – February 17, 2013) was an American author, speaker, and organizational consultant. He emphasized the importance of understanding transitions as a key for organizations to succeed in making changes. He says transition is the psychological process of adapting to change. Transition consists of three phases: letting go of the past, the "neutral zone" where the past is gone but the new isn't fully present, and making the new beginning.
He was educated at Harvard (BA, English), Columbia (MA, American History) and Brown (PhD, American Civilization) Universities  and taught American Literature at Mills College until 1974,when he became a consultant.
- Managing Transitions ISBN 0-7382-1380-2
- Transitions ISBN 0-7382-0904-X
- The Way of Transition ISBN 0-7382-0529-X
- Creating You & Co ISBN 0-7382-0032-8
- Managing Transitions p 4,5
- "Obituary". NY Times. March 3, 2013. Retrieved 1 February 2018.
- "William Bridges, Larkspur author of books on life changes, dies at 79". marinij.com. Retrieved 2017-12-12.