Prescott was born in Palmers Green, London, and is six minutes younger than her twin sister Kathryn Prescott, who is also an actress. She also has a younger brother. She received her primary education at Palmers Green High School, secondary schooling at St. John's Senior School, and finally Ashmole for her Sixth Form College education. She has also studied television production with a special in directing at university. Prior to professional acting Prescott and her sister attended weekly drama classes where they would eventually meet future co-star Lily Loveless.
She was represented by Matt Wynter of Insanity Artists Management, Prescott is now represented by Ken Mcreddie Associates.
Though Prescott made her acting debut in a single episode of the BBC soap opera Doctors ("Dare, Double Dare, Truth") along with sister Kathryn in 2008, it wasn't until the following year when she appeared as Katie Fitch in the third series of Skins that she made a breakthrough in acting. She and her sister, who plays Katie's identical twin Emily Fitch on the show, began filming the third series of Skins in July 2008 and went on to reprise their roles for the fourth series of the show as well.
Since the show's format is limited to only two series per "generation" of characters, neither Prescott nor her co-stars joined the fifth series as a major part of the cast, making her a part of the second generation.
In relation to her work with Skins, Prescott has appeared as a correspondent at open auditions for the show, the official "Skins Parties", and at Channel 4's T4 On The Beach with the cast on a number of occasions.
Following her completion with the Skins series Prescott expressed worry for her future in acting, however she has brushed it off as a reasonably common fear and has expressed strong interest in starring in the American television show Desperate Housewives, of which she is a fan. On her sister's official blog Kathryn revealed that the siblings may take a gap year to possibly volunteer with an animal sanctuary in Malaysia or Florida.
Prescott was included in AfterEllen's Hot 100 List for 2010 ranking at #68 for sexiest women.
In 2011 Prescott once again made it into the AfterEllen's Hot 100 List ranking at #87 for sexiest women.
Megan was recently cast as Jade Podfer on the British drama show called Holby City and in a horror movie Shortcuts To Hell: Volume 1.
|2008||Doctors||Charlotte "Cookie" Wilcox||Episode: "Dare, Double Dare, Truth"|
|2009–2010||Skins||Katie Fitch||Main cast member|
|2009||T4 on the Beach 2009||Herself|
|2009||BBC Switch Live||Herself|
|2009||Big Brother's Little Brother||Herself||Two episodes|
|2010||The Paralympic Show||Herself|
|2010||100 Greatest Toys||Herself|
|2012||Silent Witness||Gemma McAteer||Episode: "Domestic"|
|2013||The Meeting Place||Hazel||Short film|
|2013||Shortcuts to Hell: Volume 1||Possessed girl|
|2013||Holby City||Jade Podfer|