Pollock, who was playing for England under-20s earlier this year, has made an irresistible case since then, capping it off with a superb display for Northampton against Leinster in front of Farrell last week and will now be on the plane to Australia.
After confirming the widely expected appointment of Maro Itoje as captain, the rest of the tourists were revealed in alphabetical order as forwards, then backs.
Pollock's name got the loudest cheer from the near-2,000 fans who paid 65 pounds ($86.68) to watch the event at London's O2 Arena.
There was no place for Andy Farrell's son Owen or Ireland's Sam Prendergast as the three flyhalf berths went to Marcus Smith, Fin Smith and Finn Russell.
The last name to be read out was Tomos Williams, who joins flanker Jac Morgan as the only Welshmen in the squad.
Williams will battle with England’s Alex Mitchell and Ireland’s Jamison Gibson-Park - one of an incredible 12 Leinster players in the squad - for the number nine jersey.
It must have been hard listening for Ben Curry, who missed out as his brother Tom made the list in the hyper-competitive back row area.
Scotland centre Sione Tuipulotu was also in, despite missing the Six Nations with a chest injury. Fellow Scots Duhan Van der Merwe and Blair Kinghorn, also currently injured, made the cut.
Toulouse-based Kinghorn is likely to miss up to the first three games of the tour as his team competes in the French Top-14.
"First and foremost can I just say congratulations to everyone who has been selected, it's a special day. It's something they'll remember forever," Farrell said.
"Commiserations to those who thought they would be selected today. But things happen on tour or before you get on the plane as well. So everyone who has ambition, keep fighting, stay fit and we will be watching."
The Lions kick off with a game against Argentina in Dublin on June 20th. They will have five tour games before the first test in Brisbane on July 19th. The second and third tests are on July 26th and August 2nd.
Lions Squad:
Forwards: Tadhg Beirne, Ollie Chessum, Jack Conan, Luke Cowan-Dickie, Scott Cummings, Tom Curry, Ben Earl, Zander Fagerson, Tadhg Furlong, Ellis Genge, Maro Itoje (captain), Ronan Kelleher, Joe McCarthy, Jac Morgan, Henry Pollock, Andrew Porter, James Ryan, Pierre Schoeman, Dan Sheehan, Will Stuart, Josh van der Flier
Backs: Bundee Aki, Elliot Daly, Tommy Freeman, Jamison Gibson-Park, Mack Hansen, Huw Jones, Hugo Keenan, Blair Kinghorn, James Lowe, Alex Mitchell, Garry Ringrose, Finn Russell, Fin Smith, Marcus Smith, Sione Tuipulotu, Duhan van der Merwe, Tomos Williams