[7] Three days later he had his first start for the club in a 1–1 draw with Brighton & Hove Albion, he had several chances to score during the match including a header that hit the woodwork.

[14] Lawrence said that he hoped Ledley would stay at Cardiff for the next few seasons and that he wouldn't be surprised if the 18-year-old earned a full Wales call-up in the near future.

Ledley was identified as one of the key players in Cardiff City's team, his pace on the left wing being vital to their tenacious style of play.

[23] On 25 September, Ledley scored in a 3–0 win over Southend United to confirm Cardiff's status as early season favourites.

[28] Ledley began the 2007–08 season in great form and earned several man of the match awards in the first four months and in October 2007 he signed a two-year extension to his contract at Cardiff City.

[citation needed] Despite the speculation about his transfer Ledley himself stated that he was desperate to stay at Cardiff but concedes that he may have no choice should a high offer be made.

[33] His form continued into February and early March before a hamstring injury forced him to miss several games, including Cardiff's 2–0 FA Cup quarter final victory over Middlesbrough.

On 1 September 2008, the final day of the summer transfer window Stoke made a second bid, reported to be around £6m, but this too was firmly rejected by Cardiff.

[37][38] He scored his first goal of the 2008–09 season during a 2–1 win over Crystal Palace on 15 November[39] when he fired in after returning to the pitch after receiving treatment due to a dislocated finger.

[45] His performances in the absence of McPhail, which later earned him the Championship player of the month award for January,[46] meant that he kept the Irish international out of the side as he continued as stand in captain, including a 0–0 draw with Arsenal in the fourth round of the FA Cup.

[47] The January transfer window saw increased speculation about Ledley's future and Cardiff City turned down two bids from Premier League sides West Ham United, who saw an offer of £5m turned down,[48] and Wigan Athletic, who had a bid of £4m and former Cardiff player and Wales international Jason Koumas rejected.

[50] With only one year left on his contract, the end of the season saw increased speculation over his future, mostly from Hull City, whose manager Phil Brown attended the Bluebirds pre-season friendly against Celtic.

[56] However, Ledley received backing from both Cardiff City manager Dave Jones and club captain Mark Hudson,[57] before later stating that he needed surgery on a hip injury that had plagued him for the previous three months and subsequently hindered his performances.

[60] On 29 January 2010, Ledley underwent surgery on his hip problem which was expected to rule him out for the rest of the season,[61] but made an early return as a substitute during a 2–1 win over Swansea City.

[62] On 17 April, Ledley scored against Queens Park Rangers at Loftus Road to ensure Cardiff a 1–0 win and also a Championship Play-Off place for that season.

[70] By the end of August, the arrival of Honduran left-back Emilio Izaguirre saw Ledley return to his more familiar midfield role.

"[74] Manager Neil Lennon also defended Ledley after the match, describing referee Craig Thomson's decision as "ridiculous".

He scored with a glancing header in the first half to equalise an earlier goal from Rangers, but the Ibrox club eventually ran out 2–1 winners after extra time.

[78] A hamstring injury sustained in a league game against Rangers on 24 April 2011 ruled Ledley out of action for the rest of that season, with him missing out on Celtic's 3–0 win over Motherwell in the Scottish Cup Final.

[96] Ledley featured in both legs of Celtic's next qualifier against Helsingborg, which the club won 4–0 on aggregate to progress to the group stages of the Champions League.

These results helped Celtic qualify for the last 16 round of the Champions League, albeit where they were comfortably beaten 5–0 on aggregate by Juventus, with Ledley only featuring in the second leg in Italy.

Ledley continued to play regularly for Celtic throughout 2012–13 and captained the side on several occasions in February and March 2013 due to the absence of the injured Scott Brown.

[100] Ledley collected more silverware at the end of season, scoring Celtic's third goal in a 3–0 win over Hibernian in the Scottish Cup Final.

On 29 January 2014, Ledley opening the scoring in a 4–0 win over Kilmarnock with his fifth goal of the season, a powerful low shot past goalkeeper Craig Samson.

[108] He scored on his debut on 8 February in a 3–1 home win against West Bromwich Albion, heading from a corner taken by fellow new signing Tom Ince.

[111] Pulis praised him for his performance at Cardiff, and his general play since joining Palace, stating "He's brought a little bit of class.

[113] Ledley helped Crystal Palace to eventually finish the season in eleventh place in the Premier League, in mid-table and comfortably clear of relegation.

[114] The following season, playing in his favoured central midfield spot, he scored crucial goals in victories against Liverpool and Leicester City.

[15] In May, Wales manager John Toshack, when talking about the impact of captain Ryan Giggs retiring, said that he was hopeful for the future because Ledley along with other left-sided youngsters Gareth Bale and Lewin Nyatanga were all very talented players who could play for the national team for years to come.

[149][150] Ledley has been criticised for not being a very quick player,[151][152] some critics have suggested that several Premier League clubs who were interested in him may have been put off by his lack of pace.