Some commentators such as showbiz correspondent Dan Wootton have criticised Meghan’s decision to work with the fashion bible, with him telling ITV’s Lorraine programme: “Royals don’t guest edit magazines, celebrities guest edit magazines.”
But the duchess isn’t the first member of the Royal Family to be a guest editor.
The Duchess of Cambridge took on the role for a day at the Huffington Post UK in February 2016, when she wrote a blog about the importance of young children’s mental health.
Kate also commissioned contributions from a number of leading figures in the mental health sector as well as from young people, parents and teachers.
It was Prince Harry’s turn in 2017 when he guest-edited BBC Radio 4's Today programme, which focused on the armed forces, mental health, youth crime and climate change.
He also pulled in some huge guests to interview as part of the show - none other than former US president Barack Obama and his father Prince Charles.
Harry said at the time: "I haven't done that many interviews but it was quite fun, especially interviewing President Obama.
"It's been a big learning curve, but also these are incredibly important topics that I think we all need to think about that need to be discussed and I'm incredibly fortunate to have a platform like this."
The interview aired just a month after he and Meghan announced their engagement.
Last year, the Prince of Wales turned guest editor for Country Life magazine to mark his 70th birthday.
In the issue, he wrote about the importance of protecting rural Britain and preserving it for our children and grandchildren and commissioned articles relating to the arts, architecture and wildlife.
That wasn’t Charles’ first stint as guest editor - he collaborated with the magazine in 2013 to mark his 65th birthday. He also helped to create an edition of BBC’s Countryfile earlier this that year, to celebrate its 25th anniversary.