“I am obviously extremely saddened to finish the way we did in this World Cup and to step down from the role," said Lancaster.
"As I have always said, I ultimately accept and take responsibility for the team's performance and we have not delivered the results we all hoped for during this tournament.
"I did, however, want to take part in the review to ensure I understood the views of others before making a decision.
"The reality is that, while many aspects of the review were very positive, we didn’t achieve success on the field when it mattered and we all have to take responsibility for that but me especially as head coach.
I took on the role in difficult circumstances and it has been a huge challenge to transition the team with many hurdles along the way. However, I am immensely proud of the development of this team and I know that there is an incredibly strong foundation for them to progress to great things in the future.
"We have played some excellent rugby and it was always going to be tough to get the right level of experience into them in time for 2015. It is a young group of players with the huge majority available for the Rugby World Cup in Japan in 2019, where I believe their recent experience will make them genuine contenders.”
Lancaster was appointed England coach on a full-time basis in April 2012 and his record reads 28 wins from 46 Test matches.
However, Lancaster was never able to capture the Six Nations, coming second in the past four editions of the tournament, and his ultimate legacy is the huge disappointment suffered at the World Cup.
The RFU says the process to find his replacement is "beginning immediately".
Stuart Lancaster faces the press
Image credit: AFP
Ian Ritchie, RFU CEO added, ''The Rugby World Cup was hugely disappointing for everyone associated with the England team and the subsequent review into the team’s performance was always intended to be extremely comprehensive, which it has been.
"Stuart has been fully involved and has given feedback as well as the other coaches, players, management and a wide variety of people from around the game.
"Following the review, Stuart and I met, where we agreed that he should step down as head coach. This was subsequently ratified by the RFU Board.
“On behalf of all fans of the England team and the RFU I would like to express our gratitude to Stuart for all he has done for England Rugby since taking the role in 2012.
"Despite the results during this World Cup he has much to be proud of, and has embedded a new group of players that will be representing England for a long time to come. Looking forward, we will leave no stone unturned to ensure England achieves sustained success in the future.”