Former Wales captain Matthew Rees completed a season in which he underwent testicular cancer treatment by being named in the squad to tour South Africa in June.
Uncapped scrum-half Gareth Davies, fly-half Matthew Morgan, wing Jordan Williams and utility back Steven Shingler are also in the 32-man squad.
England-based wing George North and prop Paul James are included.
Lock Alun Wyn Jones leads Wales in place of injured Sam Warburton.
Rees, 33, has won 33 caps since making his debut in 2005 and a neck injury prevented him leading them into the 2011 World Cup.
He joined Cardiff Blues after eight seasons at Scarlets ahead of the 2013-14 season.
But Rees was diagnosed with cancer in October and had to relinquish the Blues captaincy and his place in the team to undergo treatment.
He returned in March and made enough of an impact to earn the role of Possibles skipper as they were beaten 55-7 by the Probables in Friday's trial.
That was held ahead of the tour squad announcement.
Morgan, who leaves Ospreys for Bristol this summer, is arguably the biggest surprise in the tour party.
At 5ft 8in tall and weighing a little over 11st, the 22-year-old has his chance after an impressive display as a second-half Possibles replacement at full-back.
He has also been largely an Ospreys understudy to Wales incumbent Dan Biggar and 2013 World Under-20 player of the year Sam Davies.
However, Davies does not make the tour squad.
Morgan's display at Liberty Stadium in the trial prompted Wales coach Warren Gatland to say: "The beauty about tonight was one or two players - and particularly one - came from nowhere and came on in the second half and made an impression.
"I suppose that's the romance of the trial someone can produce something, do something and get their name on the touring sheet and I thought that was special about tonight."
Scarlets wing Jordan Williams, 20 also belongs to a style of play at odds with the global trend for large, powerful players.
Like Morgan, Williams is an elusive, pacey attacker who relies on guile rather than size and strength.
Scarlets scrum-half Davies, 23, has been tipped to challenge Racing Metro's British and Irish Lions half-back Mike Phillips, 31, who has won 85 caps.
Steven Shingler, 22, joins back-row brother Aaron - also Scarlets - having flirted with Scotland in 2012 via family heritage.
However, the International Rugby Board ruled Steven Shingler was tied to Wales after he was deemed to have played in what was classified as a national "capture" Under-20 fixture.
The squad was named after a trial at Swansea's Liberty Stadium in which Jonathan Davies scored a hat-trick as for the Probables.
Scarlets tight-head prop Samson Lee, 21, who came on as a Probables replacement, left with his left arm in a sling.
And despite being named in the tour party, he is considered a serious doubt to have the chance to add to his three caps.
Lions centre Jamie Roberts, 27, and with 56 caps also left the fray with a shoulder problem.
And 27-year-old Probables hooker Ken Owens also limped out of the action, but he and Roberts are expected to go to South Africa.
Gatland also named Racing Metro's Lions flanker Dan Lydiate, 26, despite his absence from the trial with a hamstring strain.
Lions Full-back Halfpenny and open-side flankers Warburton and Justin Tipuric were ruled out by shoulder injuries.
Fly-half Rhys Priestland suffered a knee blow, while centre Scott Williams and lock Bradley Davies had respective shoulder and hamstring problems.
Lions hooker Richard Hibbard also had a shoulder issue, while back-five forward Ryan Jones has undergone ankle ligament surgery this week.
England-based players were ruled out of involvement in the trial when Aviva Premiership clubs refused to allow their Welshmen to play.
And Leicester fly-half Owen Williams' six-week ban for foul play ruled him out of contention.
North, of Northampton Saints, is involved in Saturday's Premiership final when they face Saracens at Twickenham.
Gatland's side face a warm-up match against Eastern Province Kings in Port Elizabeth on 10 June.
That will followed by Tests in Durban on 14 June and in Nelspruit a week later.
Gethin Jenkins (Cardiff Blues), Paul James (Bath), Adam Jones (Ospreys), Rhodri Jones (Scarlets), Samson Lee (Scarlets), Aaron Jarvis (Ospreys), Ken Owens (Scarlets), Matthew Rees (Cardiff Blues), Scott Baldwin (Ospreys), Alun Wyn Jones (capt, Ospreys), Luke Charteris (Perpignan), Jake Ball (Scarlets), Ian Evans (Ospreys), Aaron Shingler (Scarlets), Josh Turnbull (Scarlets), Dan Lydiate (Racing Metro), Taulupe Faletau (Newport Gwent Dragons), Dan Baker (Ospreys).
Mike Phillips (Racing Metro), Gareth Davies (Scarlets), Rhodri Williams (Scarlets), Dan Biggar (Ospreys), James Hook (Perpignan), Steven Shingler (Scarlets), Jonathan Davies (Scarlets), Jamie Roberts (Racing Metro), Cory Allen (Cardiff Blues), Alex Cuthbert (Cardiff Blues), George North (Northampton Saints), Jordan Williams (Scarlets), Matthew Morgan (Ospreys), Liam Williams (Scarlets).