Vicky will play successful career woman Emma Averill, who fears she might be losing her mind when her "hard-won dream life starts to turn into a nightmare."
The actress will star alongside Downton Abbey and The Gold star Tom Cullen, who is set to play Emma's loving husband Robert.
Meanwhile, The Walk-In's Leanne Best plays Emma's estranged sister Phoebe, and Hysteria actress Corinna Marlowe portrays Emma's mother Patricia.
Rounding out the main cast are Smylie Bradwell (Wisting) and India Fowler (The Nevers) as Emma and Robert's children, Will and Chloe.
Dominic Tighe (Suspicion) and Jade Harrison (Wedding Season) also appear as Emma and Robert's close friends Julian and Michelle Simpson, with Lyndsey Marshal (Inside Man) playing Emma's friend Caroline, Robert Gilbert (Killing Eve) as Faisal and Michelle Bonnard (Unforgotten) as DI Hildreth.
The full synopsis reads: "A couple of weeks before her 40th birthday, Emma stops sleeping — just as her mother had done right before she suffered a violent psychotic breakdown on the night of her own 40th birthday.
"Emma's mother always told her she’d go the same way, that she had the same 'bad blood', and now Emma's terrified it's true.
"As events worsen, Emma's world starts to unravel, and she realises that only by investigating the truth of her painful past can she find the answers to her present and prevent tragedy from striking a second time."
The six-part series is an adaptation of the thriller novel by Sarah Pinborough, who is adapting her work for the screen.
The drama comes from the producers of The Crown, Left Bank Pictures, in association with Vicky McClure's Build Your Own Films.
At the helm as director is Börkur Sigthorsson (The Midwich Cuckoos), joining Andy Harries, Jessica Burdett, Tim Bricknell and Pinborough as executive producer, while Charlotte Essex serves as producer. The series will be distributed by Sony Pictures Television.
Vicky said of the drama: "Myself and BYO Films are really excited to be working alongide Left Bank on Insomnia.
"It's a very different role for me. Sarah Pinborough has written such an exciting script. We have a fantastic cast, crew and production team all set for a very fulfilling few months ahead."
Vicky is perhaps best known for her role as Kate Fleming in the BBC's hit police drama, Line of Duty. The series, which first premiered back in 2012, follows the investigations of AC-12, a controversial police anti-corruption unit.