Jan Havel was unusual in playing his entire career in Czechoslovakia, playing with several different clubs. He was with Dukla Litoměřice in 1961-62, HC Dukla Jihlava in 1962-63, Tatra Kolin in 1963, TK Spartak Praha Sokolovo in 1963-65, ČKD Praha from 1965-75, and finally SK Slavia Praha in 1975-79. Havel was a forward who played 458 games in the Czech league, scoring 284 goals and 442 points. He led the Czech league in goal scoring and points in 1967-68 with 39 and 54, and in goals in 1970-71 with 32.
Internationally he played at the 1968 and 1972 Winter Olympics, winning a silver medal in 1968, and at the 1967, 1969, and 1971 World Championships, winning a silver in 1971 and a bronze in 1969. He never played in North America but in 1972 three Czech players were signed that year by NHL and WHA clubs – Havel, Josef Horešovský, and Tomáš Jelínek, but only Jelínek ever played in North America, as the Czechoslovakian government reneged on its agreement to let the other players leave the country.