Gaudreau was selected to play in the 2015 NHL All-Star Game in Columbus, Ohio, on January 25, 2015, and participated in the Skills Competition, garnering attention with Jakub Voráček for their antics during the shootout challenge. The shootout move, which imitated the previous move performed by Ryan Johansen (who helped seven-year-old Cole Vogt, the son of Columbus Blue Jackets trainer Mike Vogt, score a goal on Corey Crawford) went viral. Voráček, who went immediately after Johansen, "helped" Gaudreau score a goal in the same manner as Johansen did with Vogt, making fun of Gaudreau's size and youth, as his small stature in comparison to other NHLers lead some to believe he looks like a child. Gaudreau was originally named to the All-Star Skills Competition Rookie Team, limited to only the competition portion, but was promoted to the All-Star Game itself as a replacement to Sidney Crosby, who could not play due to injury. Gaudreau was named to Team Toews and recorded two assists in the game, both on goals scored by the Nashville Predators' Filip Forsberg.
On March 11, 2015, Gaudreau scored his 50th point of the season, becoming the first Flames rookie to reach the mark since Jarome Iginla in 1996–97. Gaudreau finished the regular season tied for the rookie scoring lead with Mark Stone of the Ottawa Senators. Gaudreau had 24 goals and led all rookies with 40 assists, while Stone had 26 goals. He was a finalist for the Calder Memorial Trophy as the NHL's best rookie, but the award went to Aaron Ekblad of the Florida Panthers, with Gaudreau finishing third. He was named to the NHL's All-Rookie team for the 2014–15 season.
In January 2015, Gaudreau filed a trademark application for the nickname "Johnny Hockey" in both Canada and the U.S. because he was concerned people would abuse his nickname for their own marketing gain.