The pair have been brought on board as independent consultants and will report to RFU chief executive Ian Ritchie as part of the organisation's drive to "make sure England teams have the foundations necessary for long-term success".
"I'm delighted we've got two outstanding individuals involved and this is a very positive move," said Ritchie. "Across the organisation we're continually looking at how we can do things better. In this case that means the best performance pathways, support mechanisms and programmes which ultimately result in better England teams."
McGeechan has coached the British & Irish Lions five times as well as leading Wasps to Heineken Cup and Aviva Premiership titles.
Former UK Sport performance director Keen oversaw the systems and processes that brought Britain 19 golds at the Beijing Olympics, and also played a key role in delivering the performance pathways that delivered 29 golds at the London Games.
"We have one of the greatest rugby brains of modern times allied with one of the most respected performance experts Great Britain has produced and that experience of best practice at the very top of elite sport can only benefit us," Ritchie added.
"I know they're both very excited about their involvement and I'm looking forward to working with them closely."