Boyd started his professional career with FC Kilmarnock. On the final day of the 2000/01 season in the Scottish Premier League, he made his competitive debut against Celtic Glasgow. The following season, he fought his way to a starting place and was awarded the prize in 2003 as Kilmarnock Young Player of the Year.
In September 2005, Boyd scored in the game against Dundee United all five goals in a 5-2 victory and the record in the Scottish Premier League English clubs were aware of him. However, the offers of Cardiff City and Sheffield Wednesday were rejected and Boyd stayed with Kilmarnock.
On 1 January 2006 he joined the Glasgow Rangers. When changing he renounced unusually, in half of the 40,000 pounds that had to pay him the FC Kilmarnock as a youth player premium. In his first game for his new club, a cup match in the Scottish FA Cup against FC Peterhead, he had a hat-trick. Overall, he scored in the 17 league games of the second half of the season 20 hits. Since he previously reach 17 goals for Kilmarnock, Boyd was a total of 37 top scorer, the first player to have managed this with two clubs.
In the following seasons counted Boyd of the top goalscorers in the league. In the 2008/2009 season, the Rangers striker ( rate: 0.77 goals / game ) secured with 27 goals in 35 games again the title of the scorer.
On December 30, 2009 Boyd scored five goals for the second time in a game against Dundee United ( Full 7:1 for the Rangers).
In the 2009/2010 season, Boyd was charged with 26 goals scorer in the league. On 28 May 2010, the Rangers announced that he will not extend his expiring contract.
On 5 July 2010 he signed for English second division side FC Middlesbrough. During the season he moved on 8 March 2011 on loan to also in the Football League Championship 2010/11 starting league rivals Nottingham Forest until end of season, scoring six goals in ten league.
From the season 2011/12 Boyd plays for the Turkish first division club Eskişehirspor. He signed on 8 July 2011, a three- year contract. This was completed by Boyd on December 19, 2011 as he was never paid by his own admission. Overall, it was only 76 minutes Eskişehirspor on the court.
After he refused an offer from Houston Dynamo on January 23, 2012, he moved on 30 January to the Portland Timbers in Major League Soccer. Houston held dis date still the rights within the MLS to negotiate with him, in return got the Texans a first- round pick in the MLS SuperDraft 2013.
On 11 May 2006 Boyd made his debut in the Scottish national side against Bulgaria. In the 5-1 win him reach two goals.
On October 11, 2008 Kris Boyd announced that he will make no more matches under coach of the Scottish national team, George Burley.
His decision came after the World Cup qualifiers against Norway. He was put on the bench and instead played freshman Chris Iwelumo. After the game the coach said that Kris had not shown enough power at the Rangers. After Boyd had belonged to this remark he contacted Burley and Gordon Smith, chief executive of the Scottish Football Association, and told the two that he will retire from the national team. At a press conference Burley hinted that the door to the national team is not completely closed for Boyd. It would be his choice, but he could come back at any time.
After Burley was sacked and Craig Levein took over the post of coach of the national team, Boyd announced again to want to play for Scotland. He was appointed on 22 February 2010 in the squad for the friendly match against the Czech Republic on 3 March and came on in the second half.