Muir grew up in Dalmuir, West Dunbartonshire, and attended Westbourne School in Glasgow.
At a Cannes press conference in 2011 her question regarding Nazi aesthetics resulted in a huge faux pas for Danish director Lars von Trier and his subsequent ban as persona non grata from the film festival.
She has also worked with Time's Up UK and Birds' Eye View, a charity which promoted the distribution of female-led films.
Muir has written three novels: West Coast, Left Bank and Suffragette City, and the non-fiction books, The Insider's Guide to Paris and Arms and the Woman, about the battle for female equality in the military.
Muir has also produced three documentaries of women's health with Finestripe productions in Glasgow for Channel 4.