A day earlier, Lyth, 27, was honoured by the Cricket Writers' Club as their Championship player of the season after scoring 1489 runs at 67.68 in Yorkshire's first title success since 2001. He was the leading first-class runscorer in the country and has been called up for the England Performance Programme's trip to Sri Lanka.
"It's a very proud moment to be voted for by your peers who you've played against all year," Lyth said of the PCA accolade at the annual PCA awards at Old Billingsgate in London. "It's been a fantastic season for both Yorkshire and me and I'll never forget the feeling on that Friday when we took the final wicket against Notts at Trent Bridge to clinch the title."
Lees, 21, ensured a Yorkshire double of the top awards, voted for by county cricketers. His opening partnership with Lyth was a cornerstone of the White Rose success. Lees was also similarly crowned by the Cricket Writers' Club.
"To join such a long list of illustrious players is very humbling," Lees said. "I've thoroughly enjoyed batting with Adam and we've thrived on each other's successes. But we couldn't have played how we did without the support of our bowling attack and the rest of the team."
Angus Porter, chief executive of the players' union, added: "Many congratulations to Adam and Alex. The list of past winners bears testament to the fact that the people best placed to judge outstanding performances are fellow professionals."
The team of the year featured Lyth and three other Yorkshiremen, Joe Root, Gary Ballance and Jack Brooks, who led the county's attack with 68 wickets at 28.02 - the third-best haul in the country. Kent's Darren Stevens, who was also named NatWest T20 Blast player of the year, was included, along with Jeetan Patel, who was the most successful spinner in the country and played a key part in Warwickshire reaching both one-day finals.
Reg Hayter Cup for the PCA Player of the Year Adam Lyth (Yorkshire)
John Arlott Cup for the PCA Young Player of the Year Alex Lees (Yorkshire)
ECB Special Award David Collier
PCA Special Merit Award Micky Stewart
NatWest T20 Blast Player of the Year Darren Stevens (Kent)
Royal London One-Day Cup Player of the Year Paul Collingwood (Durham)
Sky Sports Sixes Award Luke Wright (Sussex)
England FTI MVP of the Summer James Anderson (Lancashire)
Waitrose Women's Player of the Summer Charlotte Edwards
Investec Test Player of the Summer James Anderson
Team of the Year
Adam Lyth (Yorkshire)
Daryl Mitchell (Worcestershire, capt)
Alex Hales (Nottinghamshire and England)
Joe Root (Yorkshire and England)
Gary Ballance (Yorkshire and England)
Tom Smith (Lancashire)
Darren Stevens (Kent)
Jos Buttler (Lancashire and England)
Jack Brooks (Yorkshire)
Jeetan Patel (Warwickshire)
James Anderson (Lancashire and England)