[6] He signed for the club on professional terms at the age of 18 in 2005, and subsequently made the step up from the academy squad to playing regularly for the reserve side.
[6] To further aid Smith's development, he was loaned out to Championship side Queens Park Rangers (QPR) on an initial one-month agreement in September 2006.
[14] He scored again three days later, on 17 October 2006, hooking in a volley from a corner to briefly restore parity in a match QPR would go on to lose 2–1 to Derby County, subsequently ending their unbeaten run.
[16] Shortly after the loan extension, Smith went on to score three times within the space of a week; firstly netting a brace in a 4–2 home victory over Crystal Palace,[17] before poking in Lee Cook's free-kick in a 3–2 away win at Luton Town.
[19] Ahead of the 2007–08 season, in July 2007, Smith joined Championship side Norwich City on a loan deal that would run until the end of December.
[22][23] Smith finally made his competitive debut for Norwich on 23 October 2007, coming on as a late substitute in a 2–1 defeat to Burnley at Turf Moor.
[25] After the game against Wolves, Norwich manager Glenn Roeder confirmed he had been in talks with Chelsea's sporting director, Frank Arnesen, with a view to extending Smith's time there until the end of the season.
[29] He made his debut for the club on the opening day of the season, replacing Jermaine Johnson with twenty minutes remaining in a comfortable 4–1 win over Burnley at Hillsborough.
[32] This was not helped by the first red card of his career in a 3–1 away defeat to Birmingham City, receiving a four-match ban "for leading with his elbow in a challenge on Stuart Parnaby".
[33] After serving the suspension, Smith was unable to hold down a place in the Sheffield Wednesday first-team, returning to Chelsea upon the expiry of his loan deal in early January 2009.
[35] Smith made 16 appearances during the successful loan spell,[32] scoring once, as the club went from inside the relegation zone to finishing comfortably in mid-table during his three-month stay.
[6] The 2009–10 campaign began with Smith scoring the winning goal on the opening day of the season, lifting the ball over Fraser Forster with just twenty minutes remaining to earn Orient a 2–1 victory away at Bristol Rovers.
[48] Later that month, Smith scored another decisive goal in the FA Cup, this time as Orient disposed of Swansea City at the Liberty Stadium after securing a 2–1 victory.
[49] The win set up a Fifth Round tie at home to Premier League side Arsenal, with Smith playing the whole game as Orient took the North London club to a replay following a 1–1 draw.
[46] The first of these goals came courtesy of a "powerful header" in a 4–1 home win over Bristol Rovers on 12 February,[51] before scoring twice three days in a 3–2 victory over Milton Keynes Dons at Stadium mk.
[58] Smith netted his first goal of the campaign on 27 August 2011, heading in Dean Cox's centre to give Orient a brief lead in a match they ultimately lost 2–1 at home to Carlisle United, meaning the club had opened the season with five straight defeats.
[59] He doubled his tally for the season a month later in a 1–1 draw with Colchester United, when he "tapped in" from close range in injury-time to help Orient earn only their second point from their opening seven league matches.
[60] He went on to score in comfortable victories over Rochdale and Bromley to end the year in positive fashion as Orient began to climb the League One standings.
[64] His seventh and final goal of the season came in a 2–0 home win over local rivals Brentford on 17 March 2012, collecting Ben Chorley's flick-on before finishing calmly to double Orient's advantage in the match.
[70] He ended the season by scoring his third goal of the campaign with a first-time lob over the advancing Dean Bouzanis in an eventual 1–1 draw with Oldham Athletic at Brisbane Road on 27 April 2013.
[75] Smith made his first-team debut on 17 August, starting against his former employers, Leyton Orient, and playing the first 73 minutes in a 1–0 home defeat.