The actor originally pulled out of Saturday night's show ‘due to medical reasons.’ It was initially thought that she would return to the show the following week.
However, Strictly’s companion show, It Takes Two, confirmed on Monday that she was dropping out of the competition entirely.
The Sherlock star wrote on Instagram:
"It is with deepest regret that I had to leave Strictly. I did not come to this decision easily or lightly but for personal reasons I am unable to continue.
"It was an absolute joy working with my fellow contestants, they are a beautiful, hardworking and talented group of people who I love and who I will miss seeing every Friday and Saturday and competing alongside.
"I want to thank the incredible production team and everyone on Strictly who looked after me and who are so kind and caring.
"It's a wonderful bunch of people and I'll miss all of them. I'm so sad that I am unable to go any further.
"Thank you to everyone who voted and who sent wonderful messages and inspiring support. You are all amazing. Truly. Thank you. Xxx"
Following Abbington’s announcement, her professional dance partner on the show, Giovanni Pernice paid tribute to her on Instagram:
"Amanda... I am so sad we can't continue but I am proud of what we achieved and I am sending you so much love," he said.
Abbington is best known for playing Mary Morstan in the BBC hit detective series Sherlock, and Josie Mardle in Mr Selfridge.