It is a move which removes the potential for a scenario in which all currently contracted coaching staff could theoretically decide to move from Wales at the same time following the next Rugby World Cup.
It is currently commonplace throughout rugby for senior coaches to be contracted up to and including Rugby World Cup competitions.
Howley is a key member of Warren Gatland's coaching team and has been his assistant coach in charge of attack since 2008.
He played for Bridgend and Cardiff winning 59 caps for Wales, 22 as captain before joining London Wasps where he completed his playing career.
Howley also earned selection for two British and Irish Lions tours to South Africa in 1997 and Australia in 2001 where he won two Test caps.
He started his coaching career at Wasps under Warren Gatland before moving to Cardiff Blues from where he was recruited to the Wales coaching line up.
He said: "I have thoroughly enjoyed the time I have spent with the national team so far so I am delighted that work can now continue at least until 2016.
"As a coaching team we have achieved a lot of our aims in recent years but there are still a lot of exciting and challenging opportunities ahead. We have the right structures and systems in place, a team brimful of young talent alongside some valuable experience and a mouth watering fixture schedule.
"I am personally ambitious to become the best coach I possibly can be and it is fantastic for me to be able to continue to advance my skills here in Wales with the Welsh team. As a coach I understand the importance of continuity and I know the strengths and weaknesses of our players and the youngsters who will be challenging for selection in the near future.
"I want to spend the next few years focused on Welsh success and I am determined to develop my own repertoire of skills so I can make a valid and worthwhile to rugby in Wales.
"I am a proud Welshman and anyone who works with me knows I want nothing more that success for Wales. The Rugby World Cup proved to us as a coaching team that we are heading in the right direction and that just inspires me for the future."
Wales Head Coach Warren Gatland, said: "I am delighted that Rob will be working with us through until the next Rugby World Cup and will be continuing that work on into 2016.
"When I asked him to join the coaching team in Wales I knew the level of professionalism and skill he would bring with him and that has proved to be the case.
"He is already an accomplished coach, but I know the experience and opportunities he will have in the years ahead will improve him even more.
"There is a lot of hard work ahead, but the coaches around me have grown in stature over our time together and the continuity we now look forward to will help us achieve our aims.
"At this level we are often criticised if our performance doesn't meet outside expectations, but the biggest endorsement I can give of Rob is that, after the Lions experience in 2009, a high number of players commented to me that he was the best backs coach they had worked with, which speaks volumes."
Howley signed his new contract for Wales following close discussion with Warren Gatland and detailed negotiations with the Group Chief Executive of the Welsh Rugby Union, Roger Lewis.
Lewis said: "I am delighted Rob has decided to commit his coaching future to Wales through to the summer of 2016 at least.
"I viewed it as vitally important for us to retain a coach of his stature in an agreement which ensured Wales achieved coaching continuity after the Rugby World Cup in 2015.
"Moreover Rob has also agreed to work with Joe Lydon our Head of Rugby to assist in the development of our National Academy age grade teams.
"We know we now have in place, under Warren Gatland, a coaching line up which is the envy of the rugby world and there will be intense pressure from other nations for their services when the opportunity arises.
"That is right and proper, but the systems and structures the WRU have put in place must be retained and developed for the benefit of Welsh rugby as whole.
"Rob is a good man and a determined and talented coach who I know will take every opportunity to develop and expand his skills in the years ahead.
"We have created an environment here in Wales which helps players and coaches achieve their full potential. We will ensure those systems and structures remain robust and continue to develop. "This has been achieved by the sound financial management of the WRU.
"With Warren and his coaching team of Rob, Shaun Edwards, Neil Jenkins and Robin McBryde now in place we can look forward to some exciting and engaging rugby ahead from the national team.
"I must also pay fulsome tribute to the unsung heroes of the coaching team Prav Mathema, Adam Beard and Rhys Long. Their contribution this year to Welsh rugby has been immense. Most importantly they also will advise on the development of our National Academy.
"Our future, based upon long term planning around the right people, is very exciting indeed."