Junior The
Guelph Storm of the
Ontario Hockey League (OHL) drafted Ratcliffe in the first round, 15th overall, of the 2015 OHL Priority Selection. He joined the team for the
2015–16 OHL season, scoring his first
junior ice hockey goal on October 3, 2015, against
goaltender Evan Cormier of the
Saginaw Spirit. Ratcliffe finished his first season in Guelph with five goals and eight assists in 46 games. His rookie season was limited by a number of injuries, but he soon saw an offensive surge during the
2016–17 OHL season, with seven goals and 10 assists in the first 19 games of the season. With 43 games into his sophomore season, Ratcliffe had nearly tripled his previous-season totals, with 20 goals and 18 assists, and he was one of two Guelph Storm skaters named to the 2017
CHL/NHL Top Prospects Game. He finished the season with 56 points in 67 games, including a team-leading 28 goals, and was named the Storm's Most Improved Player. In June 2017, the
Philadelphia Flyers selected Ratcliffe in the second round, 35th overall, of the
2017 NHL Entry Draft, and he signed an
entry-level contract with them in August 2017. After joining the Flyers for training camp, Ratcliffe returned to the Storm for the
2017–18 OHL season. He had trouble early in the season, struggling with his speed and accuracy, but soon picked up his play with 37 goals through his first 61 games. Finishing the season with 68 points and a career-high 41 goals, Ratcliffe earned the Glad Mowatt Most Valuable Player Award, Fay Scott Memorial Award, and Top Scorer Award at the Storm's end-of-year team banquet. When the Guelph season concluded, Ratcliffe joined the
Lehigh Valley Phantoms, the Flyers'
American Hockey League (AHL) affiliate, for the end of their 2017–18 season. He played two AHL games that season, scoring his first professional ice hockey goal on April 13, 2018, in a 5–2 win over the
Bridgeport Sound Tigers. On March 18, 2019, Ratcliffe scored his 49th and 50th goals of the season in a 5–2 defeat of the
Erie Otters, making him the fifth player in franchise history to reach the 50-goal mark in a single season. He finished the regular season with 50 goals and 82 points in 65 games, and he took home the
Mickey Renaud Captain's Trophy for leadership in the OHL that spring. Ratcliffe added another 15 goals and 30 points in 24 OHL playoff games as he captained the Storm to their first
J. Ross Robertson Cup in six years and a berth in the
Memorial Cup. Although the Storm fell in the Memorial Cup semifinal round, Ratcliffe added an additional 15 goals and 14 assists in 24 games, and he was named to the
Memorial Cup All-Star Team.
Professional Ratcliffe joined the Phantoms again in 2019–20 for his first full season of professional ice hockey. He struggled with the transition from junior to professional level, particularly the greater resistance he faced from opposing skaters, but showed signs of improvement before the
COVID-19 pandemic forced the cancellation of the
2019–20 AHL season. He finished the year with six goals and 15 points in 53 games with the Phantoms. He was also limited by injuries during the
2020–21 AHL season, with two goals and six assists in only 22 games. Facing a slew of injuries to their forwards, the Flyers called Ratcliffe up to the NHL on January 27, 2022, to play on the fourth line with
Zack MacEwen and
Connor Bunnaman for their January 29 game against the
Los Angeles Kings. During the
2022–23 season, Ratcliffe was traded by the Flyers to the
Nashville Predators in exchange for future considerations on February 26, 2023. Ratcliffe played out the remainder of his contract with the Predators AHL affiliate, the
Milwaukee Admirals, increasing his offensive output in posting 16 points through 21 regular season games, and adding 3 goals in first playoff appearance in the AHL. Ratcliffe as a pending restricted free agent was not tendered a qualifying offer by the Predators and was released as a free agent. On July 18, 2023, he opted to sign a one-year contract with the lone AHL independent club, the Chicago Wolves, on July 18, 2023. On August 25, 2023, Ratcliffe accepted an invitation to attend the
St. Louis Blues 2023 training camp on a professional tryout contract. ==Career statistics==