The 25-year-old was confirmed by chief executive Mike Schmid as the club's first new signing of the summer on Friday, having already secured the services of 17 of last year's senior squad.
Former Northampton Saints, London Irish and Wasps number nine Commins, a Varsity winner with Oxford University in 2012, will combine playing in Hersham with a role in commercial property having quit full time rugby to join Ealing Trailfinders where he joins Esher from.
“Esher is a club striving for promotion to the Championship, and there is a great culture here," he said.
"There is a nucleus of talented players already in place and for me it’s a massive opportunity to be a part of something special.
“My ambition for the next couple of years is to settle down at Esher and enjoy my rugby. I would hope to add some experience to the team, but also want to learn from others players in the group.
"It is all about creating a winning culture, and hopefully I can help with that as much as possible.
“Having met Mike and Ricky initially, I could sense their drive to perform and that’s something that inspires.
"I’m really looking forward to meeting the supporters and the wider playing squad in the coming weeks and months ahead and judging by the first few sessions I’ve had with the fitness staff, the progress we are making is excellent.”
Esher have also confirmed they will take on London Scottish at Richmond's Athletic Ground on August 23.