The former cabinet minister told her local Labour Party in Barking it was a “really tough decision”.
In a video message, the 77-year-old said: “I have decided that I will not stand for re-election as your MP at the next general election.
Courageous, driven, and full of love and laughter - Margaret Hodge is a brilliant friend and it tugs at my heartstrings that she’s standing down.
But if anyone’s earned a change of pace it’s her! https://t.co/4zAsXxPddf
— Peter Kyle MP (@peterkyle) December 2, 2021
“I will be standing down from Parliament, it’s been a really tough decision.
“I love the job. I wanted to thank you all for the warmth, the friendship, the support and the love that you’ve shown me down the years.”
She added: “We’ve done fantastic things together.”
Dame Margaret said her proudest moment was beating then-British National Party leader Nick Griffin in the 2010 election.
“The biggest, biggest success and the biggest moment in my life was really our campaign to get rid of the BNP and see them off.”
She said she would always remember a speech when she “told them to pack their bags and go”, and “that is still absolutely stamped on my heart as a massive moment”
She added Labour was now a very different party to when she became an MP 27 years ago.
In recent years, she has spoken out about antisemitism in Labour, clashing with former leader Jeremy Corbyn over the issue and the party’s response to complaints.