What does it mean to be a ‘science ambassador’? This accessible book presents invaluable insights into how professional scientists can transform their career from working at the bench to becoming a public intellectual. James L. Olds draws on his 30-year-career as a science ambassador in Washington D.C., international experience and multiple leadership roles, to offer an engaging guide to the skills required to be an effective advocate for science. With a wealth of practical advice, Olds sheds light on the benefits and pitfalls of developing your role as a science ambassador and how to navigate the science ecosystem. Topics covered include understanding the science policy environment, effective science diplomacy and the negotiation of international agreements as well as managing science crises. A key focus is on the formation of new coalitions from largely disparate political groups, demonstrating how trusted relationships can be forged between unlikely allies. The book showcases the importance of seizing opportunities, assembling an effective portfolio and how to interact with political leaders to advocate for the immeasurable value of science in the public intellectual landscape. This How to guide is designed for students and academics across disciplines looking to improve their skills at science communications or considering a change of career track. Its practical focus will greatly benefit science professionals who find themselves in new leadership positions. Examples are drawn primarily from the U.S. but the principles are applicable to science ambassadors from around the world.