He steps away from Gander Green Lane for personal reasons, and isn’t expected back until the summer.
Doswell’s number two Ian Baird will manage Sutton for the remainder of this season, the club have confirmed.
The popular manager, who has been in south west London since 2008, will sit out the rest of the campaign as the U’s battle for another play-off finish.
Doswell said: “Ian and I have been together here for five years and he has been a huge part of the success we’ve had, so I’m sure he, along with Micky Stephens, Matt Gray, Seb Brown and the rest of the team will do a great job.
“I’ve been putting everything in to the job here for eleven years, and for personal and family reasons I do need to take a break now , but I’m looking forward to being back in early July refreshed and looking forward to the new season.’’
Chairman Bruce Elliott added: “It is absolutely the right thing for Dos to do, and he is leaving the management of the team in extremely capable hands while he is away.
“He and his family have the good wishes of everyone at the club.’’