He began working as a journalist and broadcaster for Formula One F1 in 1986 and later started as a media consultant for major sponsors. He joined Eddie Jordan’s fledgling F1 team for its debut season in 1991 as Press Officer before working with  Pacific Racing  and on Ford’s WRC programme before returning to Jordan Grand Prix in 1995 where he became Head of Marketing, joining the management board in 1998. Gallagher joined Jaguar Racing in 2004, remaining with the team when it became Red Bull Racing. He was appointed head of the Cosworth F1 engine business in August 2009. He has commentated on Formula One on ESPN Star Sports and BBC 5 Live and has contributed to a wide range of media channels including BBC News, Channel 4 News, CNN, CNBC and Al Jazeera News. He is a columnist and feature writer for Grand Prix Racing magazine in the UK which is part of the Motorsport Network and presents two podcasts; "At The Controls" cohosted by Jonathan Legard and "Inside Formula 1" with Mika Häkkinen. Between 2005 and 2009 Mark Gallagher was engaged by Pixar Animation Studios to consult on Formula 1 during site visits and coordinated the agreement with Formula 1 for the European launch of "Cars" at the 2006 Spanish Grand Prix.