Connolly began his career at the Syracuse Junior Crunch, for whom he scored 62 points scorer in the season 1996/97. A year later he moved to the first-class junior league Ontario Hockey League for the Erie Otters, for whom he played until 1999. In the 1998/99 season he led the points statistics with 34 goals and 34 assists and was a Top Prospects Game of the Canadian Hockey League invited. Because of the services shown in the OHL, he was selected in the NHL Entry Draft in 1999 in the first round in fifth place of the New York Islanders.
On 2 October 1999, he finally made his debut for the Islanders in the NHL ( against Tampa Bay) - his first goal and his first assist, he scored on October 10, 1999 against the Colorado Avalanche. He finished the season as the top scoring rookie of the Islanders and was in third place in assists, power play goals and points scorer, he also scored the fourth- most goals of all Islanders player. The following season he entered in all 82 games the Islanders the ice and scored ten goals and 31 assists.
During the NHL Entry Draft 2001 Connolly and Taylor Pyatt were transferred to the Buffalo Sabres of the Islanders in exchange for Michael Peca. His debut for the Sabres, he was on 4 October 2001 against the Atlanta Thrashers and scored his first goal for the Sabres on October 26 against the Ottawa Senators. He finished the season with ten goals and 35 assists and was one of five Sabres players, who denied all 82 games of the season. A year later he was after 80 games in which he reached twelve gates, and 13 assists, from the NHL for four games because of a high stick ( resulting in injury ) blocked - at that time he had completed 286 consecutive games.
Tim Connolly missed the entire 2003/04 season due to a concussion syndrome, which he had suffered since a concussion in a preseason game against the Chicago Blackhawks. During the lockout in the following season, he was in 16 games for the SC Langnau in the NLA on the ice.
Back in Buffalo, he set a new personal career record with 55 points in 63 games of the regular season. In the subsequent playoffs, he scored eleven more points in eight games, but suffered another concussion.
On July 2, 2011 Connolly signed a contract for two years with the Toronto Maple Leafs.
- Member of the national team at the U20 World Cup 1999 in Winnipeg (one goal in six games )
Awards and achievements
- 2002 NHL Young Stars Game
(End of season 2012/ 13)