The powerful midfielder won his only cap to date against San Marino two years ago.
There is also a recall for Manchester United left back Luke Shaw, who last played in the 3-1 victory over Scotland in November 2014.
The only uncapped member of the 22-man squad is Burnley goalkeeper Tom Heaton.
“Jonjo Shelvey gets another chance as he has been very impressive since the start of the season,” England coach Roy Hodgson said in a statement.
“This latest squad shows we are working a good number of players with a claim to be England regulars and secure a place in Euro 2016.
“Before that there are two matches we must focus on. The players must keep going, play well and look to win every match. I don’t want any let up and we want to win both these games.”
England play San Marino away on Sept. 5 before taking on Switzerland at Wembley three days later.
They have won all six of their qualifiers to date and four points from their next two games will guarantee them a top-two finish in Group E and automatic qualification for next year’s tournament in France.
One man who will particularly relish facing the part-timers of San Marino will be Wayne Rooney. The Manchester United striker has 48 international goals and needs one more to draw level with Bobby Charlton as England’s all-time top scorer.
Goalkeepers: Joe Hart (Manchester City), Jack Butland (Stoke City), Tom Heaton (Burnley).
Defenders: Nathaniel Clyne (Liverpool), Luke Shaw (Manchester United), Kieran Gibbs (Arsenal), Gary Cahill (Chelsea), Chris Smalling (Manchester United), John Stones (Everton), Phil Jagielka (Everton).
Midfielders: Michael Carrick (Manchester United), James Milner (Liverpool), Ross Barkley (Everton), Jonjo Shelvey (Swansea City), Ryan Mason (Tottenham Hotspur), Alex Oxlade-Chamberlain (Arsenal), Fabian Delph (Manchester City).
Forwards: Raheem Sterling (Manchester City), Wayne Rooney (Manchester United), Harry Kane (Tottenham Hotspur), Jamie Vardy (Leicester City), Theo Walcott (Arsenal).
(Editing by Ken Ferris)