The 23-year-old Wales international, who also won the main award in 2011, has scored 19 Premier League goals this season - a tally bettered only by Manchester United striker Robin van Persie with 25 and controversial Liverpool forward Luis Suarez (23).
"It's a massive honour. To be voted by your peers is one of the biggest things in the game. It's great to win it and I am delighted," Bale said.
"When you look at the list, there are some massive names on it but I couldn't have done it without the team. They have been fantastic this year and so has the manager."
His frightening pace, agility and clinical finishing have marked him out again this term and his successful switch from left wing to a roving central midfield role has also helped fifth-placed Spurs in their pursuit of a Champions League spot.
He took the main award - presented at a glittering ceremony - ahead of second-placed Suarez, last year's winner Van Persie and fellow nominees Manchester United's Michael Carrick and Chelsea pair Eden Hazard and Juan Mata.
Bale joins Cristiano Ronaldo, Thierry Henry, Alan Shearer and Mark Hughes in earning the main award twice. Ronaldo in 2007 and Andy Gray in 1977 won both awards in the same year.
Flying Bale's form has made him one of the most feared players in the Premier and Europa League and manager Andre Villas-Boas has said the Welshman's ability to take free kicks compares favourably with the likes of Real Madrid's Ronaldo.
Spurs may now expect a flurry of big-money bids for the player, especially if they fail to land a Champions League berth, but an estimated valuation of over 40 million pounds could put off suitors.
Liverpool contender Suarez was given a 10-match ban on Wednesday for biting Chelsea defender Branislav Ivanovic when the sides met at Anfield last weekend and served an eight-game suspension last season for racially abusing Manchester United's Patrice Evra.
Media reports said Suarez's name was booed at the ceremony.
The PFA Premier League team of the year was David de Gea (Manchester United), Pablo Zabaleta (Manchester City), Rio Ferdinand (Manchester United), Jan Vertonghen (Tottenham Hotspur), Leighton Baines (Everton), Mata, Carrick, Hazard, Bale, Suarez and Van Persie.
The Championship (second division) team of the year included two blasts from the past with Schmeichel and Ince named. However, they were Leicester City's Kasper Schmeichel, son of former Manchester United goalkeeper Peter and his old team mate Paul Ince's son Tom (Blackpool).