The 36-year-old intends to skate for Canada again and compete in the 2014 Winter Games in Sochi, Russia. His last World Cup race was March 6, 2010.
The Dutch broadcaster NOS reported Wotherspoon's comeback late Tuesday night.
Wotherspoon, from Red Deer, Alta., expanded on his desire to compete again in a video posted by the Kia Speed Skating Academy in Inzell, Germany. He's coached there since his retirement in 2010.
"My goal is to win a medal at the Olympics in Sochi," Wotherspoon says in the video. "The reason I have that goal is because I've never really felt fulfilled with my Olympic results so far.
"I know this is my last chance to get that fulfilment, so I'm going to do everything I can to try and find that."
Wotherspoon still holds the world record in the men's 500 metres of 34.03 seconds, which he set in 2007.
He won 67 World Cup races, three 500-metre world titles and another in the 1,000, plus four world sprint championships during his career
His Olympic silver medal in the 500 metres in 1998 is often forgotten because of a lack of medals at three subsequent Winter Games.
He was the favourite to win the 500 in 2002, but stumbled and fell. Wotherspoon was ninth in the 500 in both 2006 and 2010.
"My dream is to come back and compete in speed skating again because I want to win a medal at the Olympics in Sochi," Wotherspoon said.
"It was something that has been on my mind for years ever since I stopped skating and it's time to act. I can't keep thinking about it any more. I have to take action and live my dream because it's not something I want to regret."
Wotherspoon also tweeted Wednesday: "I want to say that I'm happy to be back in the game. It's going to be a big challenge, so thank you for all of the support."
The director of Canada's long-track speed skating team was surprised by Wotherspoon's announcement.
Sean Ireland says Wotherspoon gave no hint of his plans when they spoke two weeks ago at the Alberta Sports Hall of Fame inductions.
"When I found out last night, I sent him an email congratulating him on his decision and wishing him all the best for the upcoming season and reached out a hand in terms of how we could support and help him the process," Ireland said Wednesday in Calgary.
"It's his dream. I'd certainly support someone chasing their dreams."
Wotherspoon's road to Sochi starts with Canadian trials Oct. 17-20 in Calgary.
Canada can enter five men in World Cup sprints, so Ireland says Wotherspoon has to finish in the top-5 at trials to be named to the World Cup team.
The top 500-metre men in the world currently includes 24-year-old Tae-Bum Mo of South Korea, 27-year-old Michel Mulder of the Netherlands and 28-year-old Joji Kato of Japan.
Ireland doesn't know how difficult Wotherspoon's comeback attempt will be because he doesn't know how much training the skater has done in retirement.
"Having seen him on the World Cup tour in his coaching role, I know he did a fair bit of skating with his athletes," Ireland said. "Having seen him there, from a technical point of view, he certainly was in good form."
Wotherspoon said he intends to remain in Inzell and train at the academy with head coach Wim den Elsen and new assistant coach Jan Bos, who was once Wotherspoon's international rival.
Clara Hughes won an Olympic bronze medal in the 5,000 metres at age 37 in 2010.
But sprinting requires explosive training on and off the ice. Ireland says the question for Wotherspoon is whether his body can hold up to that kind of work.
"The sprint is more difficult because you're more prone to injury," Ireland said. "Things just aren't as supple as for younger athletes."
Wotherspoon took the 2006-07 season off and set his world record of 34.03 in his first World Cup race the following season.
Wotherspoon was inducted into Canada's Sports Hall of Fame last year. He is married to fellow speedskater Kim Weger and they have a daughter.