Delph had a successful start to the 2012–13 Premier League season, leading Villa manager Paul Lambert to call for his inclusion in the England squad.

[10] Delph impressed in the 2008–09 pre-season friendly against Barnet, earning praise from both manager Gary McAllister[11] and former Leeds player Eddie Gray.

[19] During the January 2009 transfer window, Leeds rejected another two bids from Premier League for Delph, with Bates saying: "We explained to both clubs that we don't deal in petty cash.

[33] On 23 January 2010 Delph scored his first goal for Aston Villa in the FA Cup win at home against Brighton & Hove Albion.

[36] Delph returned to action on 26 February 2011, in a Premier League victory over Blackburn Rovers, when he came on as an impromptu left-back after Nathan Baker was injured in the first half.

[citation needed] He played a neat one-two with Benteke, took the first touch to control with his favoured left foot and finished with his right within the box.

[citation needed] Delph scored for the first time in Premier League with "a goal of brutal brilliance" to complete a 3–2 win away at Southampton on 4 December.

[44] On 7 March, Delph scored the first goal as Villa defeated local rivals West Bromwich Albion 2–0 to reach their first FA Cup semi-final since 2010.

The victory prompted a pitch invasion by fans, who Delph claimed stole his captain's armband while kissing and biting him.

[45] He scored the winning goal in the semi-final on 19 April, as Villa came from behind to defeat Liverpool 2–1 and reach their first FA Cup final since 2000.

[46] On 30 May, Delph captained Aston Villa in the 2015 FA Cup Final at Wembley Stadium, where the team were defeated 4–0 by Arsenal.

[48][49] Delph never showed up for his scheduled medical, and subsequently released a statement on the Aston Villa website confirming he would be staying at the club and would not be moving to Manchester City.

[50] However, reports a week later emerged that Delph had again changed his mind and was having a medical at Manchester City ahead of a prospective move.

[51] On 17 July 2015, Delph signed a five-year contract with Premier League club Manchester City for a reported fee of £8 million, just six days after saying he would be staying at Aston Villa to captain them into the next season.

[50][52][53] He made his debut a week later against Real Madrid in the 2015 International Champions Cup at the Melbourne Cricket ground, but was substituted after 18 minutes for Jesús Navas due to injury, and City lost 1–4.

[58] He was sent off in the FA Cup defeat to Wigan Athletic in February 2018 and then suffered a muscle problem, not returning to fitness until April.

[63] On 28 August 2014, Delph was named in the senior England squad for the first time, ahead of a friendly against Norway and the first Euro 2016 qualifier against Switzerland.

[65] Five days later, in England's first match of UEFA Euro 2016 qualification, Delph made his first start and played the entirety of a 2–0 victory away to Switzerland at St. Jakob-Park, Basel.