The 28-year-old Cardiff flanker becomes the second player to be named captainfor two Lions tours, following England World Cup winner Martin Johnson.
His appointment was confirmed by tour manager John Spencer at Wednesday’s Lions squad announcement in west London, and comes four years after Warburton led the Lions in Australia.
As expected, Dylan Hartley is the third successive England captain to miss out, following in the footsteps of Chris Robshaw and Steve Borthwick, but the RBS 6 Nations champions still supply the largest contingent, numbering 16 players.
Head coach Warren Gatland has selected a 41-man squad for the 10 fixtures culminating in a three-Test series against New Zealand, including surprise call-ups for Ireland full-back Jared Payne, England wing Jack Nowell and Wales back row Ross Moriarty.
Warburton, who has won 74 Wales caps and led his country in two World Cup campaigns, is currently injured.
He suffered a medial knee ligament strain during the Blues’ Guinness PRO12 clash against Ulster earlier this month, but is only expected to be sidelined for up to six weeks.
He could even return to action for Cardiff before the Lions depart to New Zealand on May 29, if they reach the European Champions Cup qualification play-offs.
Warburton will lead a Lions squad of 19 backs and 22 forwards, and he is among 12 Welshmen selected.
Reflecting on the appointment, Gatland said: “Sam is a great player, an outstanding leader and a winning Lions captain.
“We believe that Sam’s experience and leadership qualities make him an obvious choice as captain.
“He has earned the respect of his peers and coaches through his resilience, tenacity and hard work.”
On the eve of the announcement, Warburton attended a private dinner with all the living Lions captains in the Hilton Syon Park Hotel, near Twickenham.
Warburton added: “Being in the same room as so many Lions legends was an amazing experience.
“I feel humbled and extremely proud to be given the opportunity to captain the Lions for a second tour, and look forward to playing the world champions on their own turf with the best players of the UK and Ireland at my side.”