With regular captain Alun Wyn Jones in a British and Irish Lions squad led by former Wales skipper Sam Warburton for the combined side's upcoming tour of New Zealand, Wales were on the hunt for a new on-field leader for their internationals against Tonga in Auckland on June 16 and Samoa in Apia a week later.
"I'm immensely honoured to be named captain of Wales for this year's summer tour," said Roberts, 30, in a Welsh Rugby Union (WRU) statement on Tuesday as the 32-man squad was announced.
"It's a proud moment for myself, but more importantly my family and a position of responsibility that I will take huge pride in."
Roberts added: "I am excited for the new players in the squad as they get the chance to test themselves at this level, and also for the more established players who now have a chance to become leaders in this team."
There have been alterations to the backroom staff too, with Wales boss Warren Gatland in charge of a Lions squad where interim coach Rob Howley is one of his assistants.
As a result, forwards coach Robin McBryde will be in overall charge against Tonga and Samoa.
Roberts, capped 91 times by Wales, failed to gain selection for this year's Lions after starring in the combined side's 2-1 series triumph in Australia four years ago after also featuring in their 2009 tour of South Africa.
Now at London club Harlequins, Roberts was one of the most experienced players available to McBryde after Gatland selected 12 Wales internationals in his 2017 Lions squad.
"We've got a good mix of experience and youth in this squad," said McBryde who, following the Welsh call-ups to the Lions, named 13 uncapped players in his party for the Tests against the Pacific island nations.
"The senior players will be expected to display their leadership qualities and we want the younger men to show they've got what it takes to handle the intense international environment."
One of the uncapped players is in-form back-row forward Thomas Young.
The son of former Wales and Lions prop David Young, his coach at Wasps, the 24-year-old scored three tries in a 35-15 win over defending champions Saracens on Saturday as the Midlands club finished top of the regular season English Premiership standings ahead of the title-deciding play-offs.
Others also aiming to make their Test debuts next month include Ospreys wing Keelan Giles and Leicester back Owen Williams, set to move to Premiership rivals Gloucester at the end of the European season.
However, in a Wales squad of 14 backs and 18 forwards, there was no recall for hooker Richard Hibbard.
The front-row, who won the last of his 41 Wales caps in 2015, has been in fine form for Gloucester this season and the 33-year-old is set to be a key player for the Cherry and Whites when they face Paris-based Stade Francais in the second-tier European Challenge Cup final at Murrayfield on Friday.
Wales 32-man squad announced on Tuesday for two Tests away to Tonga and Samoa in June:
Cory Allen (Cardiff Blues), Gareth Anscombe (Cardiff Blues), Alex Cuthbert (Cardiff Blues), Aled Davies (Scarlets), Gareth Davies (Scarlets), Sam Davies (Ospreys), Steff Evans (Scarlets), Keelan Giles (Ospreys), Tyler Morgan (Newport Gwent Dragons), Jamie Roberts (Harlequins/ENG, captain), Owen Williams (Leicester/ENG), Rhun Williams (Cardiff Blues), Scott Williams (Scarlets), Tomos Williams (Cardiff Blues)
Scott Baldwin (Ospreys), Jake Ball (Scarlets), Adam Beard (Ospreys), Kristian Dacey (Cardiff Blues), Seb Davies (Cardiff Blues), Ryan Elias (Scarlets), Rob Evans (Scarlets), Tomas Francis (Exeter/ENG), Ollie Griffiths (Newport Gwent Dragons), Cory Hill (Newport Gwent Dragons), Ellis Jenkins (Cardiff Blues), Wyn Jones (Scarlets), James King (Ospreys), Samson Lee (Scarlets), Josh Navidi (Cardiff Blues), Nicky Smith (Ospreys), Rory Thornton (Ospreys), Thomas Young (Wasps/ENG)
June 16: Tonga v Wales, Eden Park, Auckland
June 23: Samoa v Wales, Apia