Walton was born in Kirkland Lake, Ontario, but his family lived a transient existence during his youth before settling north of Toronto. They operated a restaurant/garage in Sutton, about 50 kilometres (31 mi) north of the city. He inherited his nickname "Shakey" from his father Bobby, who would shake his head to throw off opponents as a hockey player in England.
Walton made his Leafs debut in 1965–66, appearing in only six matches. He established himself on the veteran-dominated team midway through the next campaign. Working exclusively on power-play situations, he scored four goals with three assists while playing in all twelve games of Toronto's postseason run to the 1967 Stanley Cup Championship. He was the club's leading scorer with 59 points (30 goals, 29 assists) in 1967–68, his first full season in the league and most productive with the Leafs.
His time with the Leafs was marred by constant conflict with head coach Punch Imlach and team president Stafford Smythe. Prior to his dismissal in April 1969, the domineering Imlach, disdainful of younger players, clashed with Walton over his hairstyle and bombarded him with negative comments about his on-ice performance. Also at issue for was the fact that Walton's agent was Alan Eagleson, who helped establish the NHL Players' Association. Further complicating matters was Walton's marriage to Smythe's niece, and Conn Smythe's granddaughter, Candace. When an independent psychiatrist appointed by the NHL diagnosed Walton with depression in the middle of the 1970–71 season, his departure from the Leafs was imminent.
He was injured in a bizarre accident in the middle of the 1972–73 season when he tripped and fell through a plate glass door at a St. Louis hotel. Despite needing over 200 stitches and a complete blood transfusion after losing five pints of blood, he made a complete recovery.
Minnesota Fighting Saints (WHA)
The upstart World Hockey Association, attempting to lure talent away from the established league, conducted its General Player Draft on February 12, 1972 to evenly distribute amongst its franchises NHL players with expiring contracts. Even though still under contract with the Bruins, Walton was selected by the Los Angeles Sharks. His WHA rights were traded in June 1973 to the Minnesota Fighting Saints, who succeeded in signing him to a three-year deal worth $450,000.
He made an immediate impact as the WHA's leading scorer with a career-high 117 points (57 goals, 60 assists) in 1973–74. He continued as the team's top scorer for the next two seasons, but left the team on Feb. 25, 1976, three days before financial problems forced the Fighting Saints to cease operations.
Since his retirement from professional hockey, Walton has worked as a real estate agent for RE/MAX in Toronto. His clients have included active and former Leafs players, such as Doug Gilmour and Mats Sundin. He was the eponymous and initial proprietor of Shakey's Original Bar and Grill on Bloor Street in the western part of the city.