Johnson, who resigned as Prime Minister last year amidst a scandal around misconduct allegations against Chris Pincher, will stand down from his west London seat of Uxbridge and South Ruislip.
His announcement comes just one day after he was shown a report into whether he mislead the House of Commons over Partygate.
The 58-year-old hit out at the process that led to the report in his resignation statement, calling it a “kangaroo court”.
He said: “I am now being forced out of parliament by a tiny handful of people, with no evidence to back up their assertions, and without the approval even of Conservative party members let alone the wider electorate.
“I believe that a dangerous and unsettling precedent is being set.”
However, Labour MP Chris Bryant, chair of the Privileges Committee, told BBC Breakfast: “He is leaving as a disgraced Prime Minister.”
The resignation is set to trigger a by-election in Uxbridge and South Ruislip, which Johnson held in the 2019 general election with a majority of 7,210 over Labour.
The seat is widely regarded as a key target for the Labour Party, and it has been speculated based on poor polling for the Conservatives that Johnson was at risk of losing the seat.
However, a recent Lord Ashcroft poll in the constituency suggested Johnson would hold it with 50% of the vote.