In his third year in the NBA, Harry Gallatin was selected for the first NBA All-Star Game in 1951, and from 1951 through 1957 was chosen for seven consecutive NBA All-Star games. It was in the NBA where he earned the nickname “The Horse”. He played his entire career as an extremely undersized center at 6’6″ and 215 lbs., but had more than size and passion; he had tremendous physical strength and epitomized hard work both in college and in the NBA. He played nine seasons for the New York Knicks, from 1948 to 1957. His best statistical year was in 1954, when he led the NBA in rebounding, averaging 15.3 rebounds per game. That same year, he was also named to the All-NBA first team. His most dominating single-game performance was on the last regular season game of the 1952–53 season. That night, against the Fort Wayne Pistons, Gallatin pulled down 33 rebounds, a Knicks record which still stands today. To say rebounding was one of the things he did well was an understatement. In the six seasons he played when rebounds were recorded, he was among the leaders in the league in rebounds per game.[5] For his career, he averaged an impressive 11.9 rebounds per game. Gallatin still holds the Knick team record of 610 consecutive games. After nine strong years with the Knicks, Gallatin was traded to the Detroit Pistons in 1958. He played only one season for the Pistons before retiring as one of the most dominating post players of his era, and a very durable and dedicated athlete.

After his retirement from playing in 1958, Harry Gallatin became the head coach of the Southern Illinois University Salukis. In four seasons there, he led his teams to a 69–35 record and post-season tournament appearances every year. The 1961–62 team made it to the NCAA Small College (now Division II) Tournament semifinals before barely losing to eventual champion Mount St. Mary’s College 58–57, then took third place by beating Nebraska Wesleyan University 98–81. He returned to the NBA in 1962 as coach of the St. Louis Hawks. In his first season, he led the Hawks to the division finals and was named NBA Coach of the Year. The 1963–64 season saw the Hawks again advance to the division finals, but halfway through 1964–65 he returned to New York to coach the Knicks while Richie Guerin replaced him as coach of the Hawks. The Knicks were developing into a championship team, but the pieces were not yet all in place and Gallatin left the Knicks and the NBA midway through the 1965–66 season. He became Assistant Dean of Students at Southern Illinois University Edwardsville in 1966, then the first athletic director and basketball coach in 1967. He remained at SIUE until his retirement in 1992, where he also taught in the physical education department and was the SIUE Cougars’s men’s golf coach for 24 years, leading that team to NCAA Division II championships 19 times and finishing in the top 10 six times.

After his retirement from coaching, Harry Gallatin remained active and enthusiastic, while continuing to live in Edwardsville, Illinois. He was inducted into the Naismith Memorial Basketball Hall of Fame in 1991, and was also named to nine other Halls of Fame. In 2011, the New York Knicks honored him in their second “Legends Night Awards” along with other former Knicks stars Dick Barnett, Earl Monroe, Mark Jackson, John Starks and Allan Houston,  and in May of 2015, the Knicks added him to Madison Square Garden’s Walk of Fame. On June 24, 2013, Gallatin took part as the SIUE athletics department broke ground for a new golf training facility. Following approval by the SIU Board of Trustees, it was officially named the Harry Gallatin Golf Training Facility. Harry Gallatin died on October 7, 2015 following surgery. He was survived by Beverly Hull Gallatin, his wife since 1949, their sons, Steve, Jim, and Bill; his sister, Eileen Palmer; eight grandchildren; and six great-grandchildren.