After reading anthropology Merryl began a career in journalism. A stint in radio news was followed by work on the TV documentaries series Everyman, Heart of the Matter and Global Report and other programmes for BBC Religious Programmes.  On leaving the BBC she wrote for the influential international Muslim magazine of events and ideas,

and published her first book, Knowing One Another: Shaping an Islamic Anthropology, before moving to Malaysia where she lived for 10 years. In Malaysia Merryl was a consultant to TV 3 and continued to publish books and articles. Returning to Britain in 2000 she settled in her home town in Wales to concentrate on writing. Her work ranges from Darwin to American cinema and post colonial studies. Her collaboration with co-author Ziauddin Sardar began with their 1990 book, Distorted Imagination: Lessons from the Rushdie Affair, and more recently produced the best selling Why Do People Hate America?, the first in a trilogy of books exploring America its ethos and impact on the rest of the world.
Merryl has been active in Muslim debate in Britain and internationally for some 30 years and published widely on Islam and Muslim affairs.

In 2010 she became Director of the Muslim Institute of London. Rekindling the classical Islamic tradition of learned societies the Institute is dedicated to pluralistic thought, open debate, creativity, excellence and high achievement. It is a fellowship society of academics, writers, thinkers, artists, scientists, professionals and researchers committed to the intellectual development of Britain’s Muslims and British society as a whole.