He joined English side Norwich City in 1998, remaining there for six years. Between 2004 and 2006, he achieved consecutive promotions to the Premier League with Norwich, West Ham United and finally Watford. Mackay won five caps for Scotland towards the end of his playing career.
After retiring as a player in 2008, he became manager of Watford in June 2009. He was manager of Cardiff City between June 2011 and December 2013, achieving promotion to the Premier League in 2013 but was dismissed after a dispute with club owner Vincent Tan. Mackay was appointed manager of Wigan in November 2014. Following a poor run of results he was dismissed by Wigan in April 2015.
Born in Bellshill, Mackay began his career in his native Scotland, coming through the youth ranks of Queen's Park, before joining Celtic in the summer of 1993. He made his Celtic debut on 13 May 1995 in a 1–0 away win against Dundee United.
His first Celtic goal was scored on 27 April 1996 in a 4–2 away win against Partick Thistle. He made 46 appearances in five years with the Glasgow club, and in September 1998 moved to England, joining Norwich City for a fee of £350,000 after a one-game loan spell.
At the end of the 2001–02 season Norwich fans voted Mackay in second place behind Gary Holt in the voting for Norwich City player of the year. In the 2003–04 season, his sixth at Norwich, the club was promoted to the Premier League after winning the then Division One, however he was released by Norwich at the end of the season. He was named in the Football League First Division Team of the Year in the 2003–04 in which they got promoted. Mackay scored a brace for Norwich in an East Anglian derby against Ipswich Town.
Mackay was signed for West Ham United by manager Alan Pardew, for £300,000, on 10 September 2004. He played 18 league games for the Hammers, although none after March, as West Ham reached the play-offs, beating Preston North End in the final to reach the Premier League. Mackay was released before playing a top flight game.
Mackay was picked up on a free transfer by Aidy Boothroyd as part of his rebuilding of Watford and soon become one of the key figures in Boothroyd's side. Mackay was involved in some excellent defensive displays as well as scoring some vital goals, including one against fierce rivals Luton Town at Kenilworth Road in a 2–1 victory. At the end of the 2005–06 season Mackay achieved the feat of being promoted to the Premier League for the third successive season, as Watford defeated Leeds United 3–0 in the play-off final.
After having been released following his two previous promotion campaigns, Mackay was assured by Boothroyd that he would play a part in Watford's Premier League campaign, citing his experience as an important asset to the team. Although he was not a first-team regular, Mackay made 14 Premier League appearances in 2006–07. In January 2007, Mackay took his first step into coaching by being promoted to first team coach, following the departure of Dave Hockaday.
In the 2007–08 season Mackay's only first team appearance came during an FA Cup match against Wolves in January 2008. He took over as caretaker manager at Watford on 4 November 2008 following the departure of Aidy Boothroyd.
During his sixth and final season at Norwich, at the age of 32, Mackay became the oldest man to make his debut for Scotland in 37 years.
It came in a 1–0 defeat to Denmark; Mackay later played in a 1–0 victory over Estonia and a 4–1 win against Trinidad & Tobago. In total, Mackay won five caps for Scotland.
After Brendan Rodgers resigned in June 2009, Mackay took over as the manager of Watford. Watford drew 1–1 on their league visit to Reading on 26 September 2009, and by their second meeting late in the season Rodgers had been dismissed by Reading after only a few months in charge. As for Mackay and Watford, 2009–10 was a difficult season where their Championship status was under threat for a long time, but by the end of April survival had been achieved against Reading, ending the season 14th place in the league.
Mackay signed a three-year contract as Cardiff City manager on 17 June 2011, with Watford receiving an undisclosed fee in compensation. His reign began with a 1–0 away win over West Ham United. The side were undefeated in September, resulting in Mackay being nominated for the September Championship Manager of the Month in his first month managing the Welsh club. Another unbeaten month for Cardiff resulted in Mackay winning the award in November.
He guided Cardiff to their first ever League Cup final, following wins over Oxford United, Huddersfield Town, Leicester City, Burnley, Blackburn Rovers and Crystal Palace in earlier rounds.
The week before the League Cup final, Mackay signed a three-and-half-year contract extension, tying him to the club until June 2016. Mackay's side were beaten by Liverpool in the Wembley final, losing 3–2 on penalties, with a 2–2 scoreline after extra time. Cardiff's season ended where it began, as they were beaten 5–0 on aggregate by West Ham United in the promotion playoffs.
Following the success of his first season in Wales, Mackay was reportedly one of the candidates to replace Paul Lambert at Premier League side Norwich City. He turned down the offer and said he was fully committed to Cardiff City. He oversaw Cardiff's strongest ever home start to a league season, as they won each of their first ten fixtures at Cardiff City Stadium, the previous club record being nine consecutive home wins. Mackay went on to lead Cardiff to promotion to the Premier League, and sealed the Championship title after a 1–1 draw away at Burnley. Mackay was voted the League Managers Association (LMA) Championship Manager of the Year on 21 May 2013.
During the 2013–14 season, Mackay came under criticism from club owner Vincent Tan concerning his signings, transfer budgets, results and style of play. In December 2013, Tan told Mackay to resign from the club or be dismissed, leading to critical media comment not only of the decision but of Tan's tactics, one commentator referring to Tan as "The world's thickest Machiavelli". After a 3–0 home defeat to Southampton, Mackay was sacked by Cardiff on 27 December 2013 after a meeting with the club's directors.
Mackay was expected to become manager of Premier League club Crystal Palace in August 2014, but dropped out of contention after Cardiff City sent a dossier to the Football Association alleging misconduct by Mackay and sporting director Iain Moody. It subsequently emerged that some of the allegations related to text messages considered to be of a racist, sexist or homophobic in nature. Cardiff questioned the fees paid to agents and lawyers relating to transfer deals made while Mackay and Moody worked for the club. A source of tension between the two clubs was the alleged leaking in April 2014 of a Cardiff starting lineup to Crystal Palace, where Moody became sporting director after leaving Cardiff. Moody resigned from his position at Palace after the allegations were publicised.
Via a statement published by the LMA, Mackay apologised for writing two messages that he admitted were disrespectful of other cultures, but denied stating anything of a homophobic or sexist nature. The LMA itself apologised for characterising the messages as "friendly banter" in the statement. After conducting an investigation, the Football Association announced in July 2015 that it would not charge Mackay or Moody with any offences.
Mackay was appointed manager of Wigan Athletic on 19 November 2014, despite fan opposition, after the Championship side had dismissed Uwe Rösler. The appointment was criticised by the Kick It Out campaign, who said that the club had disregarded the ongoing FA investigation into text messages sent by Mackay. Wigan chairman Dave Whelan said that the club had inserted a clause in its contract with Mackay stating that they could terminate the contract if he is found guilty by the FA. A shirt sponsor of the club, Premier Range, withdrew their backing after Mackay was appointed.
On 22 November, in his first game as manager, Wigan drew 1–1 against Middlesbrough at the DW Stadium. He was dismissed on 6 April 2015. A 0–2 defeat to Derby County saw him leave the club eight points from safety of relegation in the division. During his 138-day tenure, Wigan achieved 19 points from a possible 72 winning 5 games of 24 played in the Championship. The move was welcomed by fans with Wigan Athletic Supporters Club spokesperson Caroline Molyneux telling BBC Sport: "I think [Mackay's sacking] is a popular decision among the fans." Mackay had received public backing by newly appointed club chairman David Sharpe as recently as March 2015 when he described Mackay as "a big part of what we are doing here".
In December 2016, the Scottish Football Association appointed Mackay as its performance director, responsible for overseeing the development of young players. The appointment was criticised by some people, including politician Clare Haughey, due to Mackay's previous behaviour. The anti-racism campaign group Kick It Out made comments that were supportive of Mackay, pointing out that he had since received equality and diversity training from the (English) FA.
Mackay's father (also named Malky Mackay) is a former footballer who played as a striker. The Mackay family are all supporters of Glasgow-based club Queen's Park. Mackay Sr. is a member of the board at the club. Mackay Jr. played for amateur side Queen's Park as a teenager, whilst working in a branch of the Bank of Scotland.As of 6 April 2015
CelticScottish Premier Division: 1997–98
Norwich CityFootball League First Division: 2003–04
WatfordFootball League Championship play-offs: 2005–06
Cardiff CityFootball League Championship: 2012–13
EFL Cup: Runner up 2011-12
Football League Championship Manager of the Month: March 2011, November 2011
LMA Championship Manager of the Year: 2012–13