Ward began his career as a trainee with Aston Villa and played in their 2004 FA Youth Cup Final defeat against Middlesbrough. He turned professional in July 2005 after recovering from injuries received in a car crash in 2004.

Although Ward captained Aston Villa’s reserve team, he did not make a first team appearance and in March 2006 he joined Stockport County on loan until the end of the season, making his league debut in a 1–0 victory away to Bury on 7 March. He made nine appearances, scoring once in a 3–1 home victory against Shrewsbury Town.

At the end of the 2005–06 season, Ward was released by Aston Villa and on 6 July 2006 he signed a three-year contract with Ian Atkins’ Torquay United, despite interest from Stockport County and Wrexham. However, with a change of ownership and manager at Torquay, Ward asked for a transfer in December 2006.

Torquay joined Chesterfield, managed by former Torquay manager Roy McFarland, on 31 January 2007 on a two-and-a-half-year contract for an undisclosed fee.

He began the 2008–09 season as a first choice, with his form attracting attention from higher-level clubs such as Derby County and Sheffield United. He rejected the offer of a new contract with Chesterfield in December 2008, with his existing contract set to expire at the end of the season. In January 2009, Championship side Barnsley made a bid for Ward for £400,000 which had been accepted. However, the move was called off after he failed to agree personal terms with the club.

Having rejected Barnsley, Ward finally agreed a three and a half-year deal with Sheffield United in January 2009 with the clubs agreeing a fee of around £330,000.

Ward scored his first goal for the Blades in only his second appearance, a 2–1 win at Southampton in February of the same year. The Blades had conceded an injury time equaliser before Ward regained the lead in the 93rd minute. He then played regularly for the remainder of the season, scoring a further goal in the process. His season finished on a low note however as he was sent off for two handballs in the 2009 play-off final against Burnley at Wembley.

Born in Birmingham in the West Midlands, Ward qualifies for Northern Ireland through his grandfather. He made two appearances for the Northern Ireland under-18 team and a further seven for the under-21 team. After a promising start to his career at Sheffield United, Ward was called into the senior team in March 2009 ahead of two World Cup qualifiers against Poland and Slovenia. Ward was an unused substitute for the two games in which Northern Ireland won back-to-back games and possibly enhanced their chance of reaching the World Cup in South Africa.

On 17 September 2011, Ward scored his first goal as a full Derby player with the equaliser against rivals Nottingham Forest, as Derby recorded a 2–1 win. The goal won the club’s Goal of the Season award. Ward started all of Derby’s (32 games, four goals) league games (bar the League Cup game against Shrewsbury Town when he was on international duty). Ward’s run of starts ended after the game against Leicester City when Ward picked up a thigh injury whilst on international duty on 29 February. Ward was out of action for five weeks, before making his first team return in a goalless draw against Ipswich Town on 7 April 2012. In the game against Cardiff City on 17 April 2012, Ward was substituted early in the second half after picking up a dead leg. Ward was fit enough to start the following game at Portsmouth.

Ward won his first full cap for Northern Ireland in a Euro 2012 qualifier against the Faroe Islands on 10 August 2011, with his first start coming in a 2–0 defeat away to Russia in their first 2014 FIFA World Cup qualifier. On 6 September 2013, Ward scored his first goal in a 2–4 home defeat against Portugal. On 28 May 2016, Jamie Ward was named in Michael O’Neill’s squad for Euro 2016.

Despite his contract still having a year to run, Derby coach John Metgod stated that the club were in contract talks with Ward during April 2012. Ward signed a new two-year contract on 19 April 2012, with an option for a further year which will extend his stay at Derby until at least the summer of 2014. Derby manager Nigel Clough stated in a July 2012 interview that Ward could feature more as a striker in the 2012–13 season.

Ward scored his first brace for the club in a 3–2 win against Charlton Athletic, a 25-yard volley and a penalty. and scored again four days later opening the scoring in a 2–1 loss against Burnley. In October 2012, Ward picked up a Grade One tear of his hamstring during the East Midlands derby game at Nottingham Forest. Two months later, on 6 December, Clough stated he was unsure when Ward would return to the squad and stated his frustration at the injury. However, a day before Derby’s game at Charlton Athletic on 29 December, Clough said that Ward was set to return to the matchday squad as a substitute after a three-month absence. Ward featured as a 68th-minute substitute and scored the equalising penalty in the 72nd minute in the 1–1 draw against Charlton. However, he picked up an injury in the match and was replaced in the 83rd minute. Ward missed the following game due to the injury.

On 2 July 2015, Ward signed for Derby’s arch-rivals Nottingham Forest on a four-year deal, after his contract with Derby had expired at the end of the season. This was a somewhat unexpected transfer, given that Ward had often played a controversial and provocative role in recent games between the two sides. Ward acknowledged this in an interview with BBC East Midlands Today, but stressed that his focus was now on Forest:

Ward scored his first goal for the club in an FA Cup tie against Queens Park Rangers on 9 January 2016. This was followed up a week later by his first league goal, and two assists, in a man-of-the-match performance against Bolton Wanderers. His good form continued with Ward scoring to secure Nottingham Forest an away victory against Middlesbrough, who were at the top of the table prior to this fixture.

On 31 August 2016, Ward was loaned to Championship rivals Burton Albion until the end of the 2016–17 season. He scored his first goal for the club in a 1–1 draw with Queens Park Rangers on 27 September 2016. On 20 January 2017 Ward’s loan to Burton was terminated, and he returned to Nottingham Forest.

On 31 January 2018, Ward joined Cardiff City on loan for the remainder of the 2017–18 season in a swap deal involving Lee Tomlin moving to Forest on loan. His debut came on 13 February against Bolton Wanderers, however, he suffered an injury 13 minutes into the game, resulting in his substitution.

On 31 August 2018, Ward joined League One side Charlton Athletic on loan until 1 January 2019.

On 25 September 2019, Ward joined League Two club Scunthorpe United on a deal until January 2020.

On 2 October 2020, Ward joined National League side Solihull Moors on a one-year deal.