Born to an ethnic Hungarian family which immigrated from Carpathia after the end of World War I when the territory was ceded to Ukraine, he is perhaps best remembered for his time playing on the famous "Uke Line" in Boston with the Bruins, with fellow Ukrainian-Canadians Johnny Bucyk and Vic Stasiuk. Horvath missed out on the Art Ross Trophy in 1959–60 by a single point to Bobby Hull, however he tied with Hull for the goal-scoring lead, with 39. He played for five of the Original Six teams in the NHL (only missing Detroit) and was demoted to the minors in 1963, however with the increased demand for players with the NHL expansion in 1967, Horvath found himself back in the league with the Minnesota North Stars. He ultimately retired from playing in 1970. The following year he became coach of the London Knights of the OHL, from 1971–72. He moved to South Yarmouth, Mass., when he was named coach of the Cape Cod Cubs, an expansion team in the Eastern Hockey League, in 1972. He coached the Cubs to a regular-season divisional championship and a sweep of their first-round playoff series with the Long Island Ducks before a powerful Syracuse Blazers team ended Cape Cod's league championship hopes. Horvath returned as coach for the 1973–74 season with the Cubs, who were charter members of the new North American Hockey League, but was fired after the team got off to a slow start. His last coaching job was a brief stint at Dennis-Yarmouth (Mass.) Regional High School. He still resides on Cape Cod, where he enjoys an occasional round of golf.