"They were the first two people I had in mind for this role," McGinley told a news conference.
"Des took me under his wing when I was a young rookie on Tour and he gave me tremendous advice.
"Sam is a man who has probably had the most influence on me in terms of playing team golf in my career.
"Being my first captain in the Ryder Cup in 2002, I learned a huge amount from him and have continued to do so over the years."
Scot Torrance, 60, led the European team to victory at The Belfry in 2002, 17 years after he holed the winning putt at the same venue.
"Everyone knows how much the Ryder Cup has meant to me over my career so I am absolutely delighted to be involved once again," Torrance said.
"Paul was a special part of my team at The Belfry in 2002 and he knows I will do everything possible to help him and the team at Gleneagles in September."
Smyth, 61, featured in the Ryder Cup as a player in 1979 and 1981.
"I was thrilled when Paul contacted me and asked me to be one of his vice captains at Gleneagles - there was no hesitation for me in saying 'yes'", the Irishman, who assisted Ian Woosnam at the 2006 Ryder Cup, said.
"I relished the opportunity to be a vice captain at The K Club in 2006 and I look forward to playing a positive role once again in supporting Paul and the team."
U.S. skipper Tom Watson has already appointed four-times major winner Ray Floyd and double U.S. Open champion Andy North as his vice-captains.
Gleneagles will be the venue when holders Europe take on the U.S. from September 26-28.
The Americans have not won the trophy in Europe since 1993, when Watson was captain for the first time.
(Writing by Tony Jimenez and Michael Hann; editing by Justin Palmer)
