He was part of the one-day set-up for Kent since 2002, but did not secure a regular place in the first-class County Championship team until 2007, a year after taking his maiden ten-wicket haul.

After impressing during the 2009 season with Kent, helping the team gain promotion back to the first division of the County Championship, Tredwell played his first Test and ODIs against Bangladesh in March 2010.

In September 2018, Tredwell announced his retirement from cricket having been injured for the entire 2018 domestic season after making five appearances in Kent's pre-season campaign in the West Indies 2017–18 Regional Super50 competition.

He made three appearances in youth Test matches for England Under-19 cricket team against the West Indies in August 2001.

He became more involved with the Championship side in 2007, scoring his maiden first-class century (116*) against Yorkshire, and returning then career-best bowling figures of 6/47 against Surrey.

[25] In March 2016 Tredwell was selected to represent the Marylebone Cricket Club (MCC) in the Champion County match against Yorkshire in Abu Dhabi.

Tredwell finally made his debut for England against Bangladesh in an ODI in March 2010, finishing with figures of 0/52 from 10 overs.

By the start of 2013 Tredwell had established himself as a key part of England's limited overs team and he played in all five matches against India, taking his best ODI figures of 4/44 during the tour.

He took 3/19 in the semi-final against South Africa and played in the rain-affected final against India, taking 1/25 as England narrowly lost by five runs.

More games followed: Tredwell played T20Is against New Zealand, captioning the side in one match which was rained off after two balls, and played ODIs against Ireland and four of the five ODIs against Australia later in the season before touring Australia over the 2013–14 northern winter and then being selected for the limited overs tour of the West Indies, in preparation for the T20 World Cup.

Despite being selected in the squad for a Tri-series tournament against India and Australia in early 2015, Tredwell did not play as Moeen Ali was chosen ahead of him as England's spin option.

He was selected for the 2015 World Cup squad but only played in England's final game of the tournament against Afghanistan as the team again failed to advance out of the group stage.