Before he moved to England, Solskjær completed a year's national service in the Norwegian army, and played part time for Third Division Norwegian Clausenengen F.K., later moving to Norwegian Premier League Molde F.K. in 1994. He joined United on 29 July 1996, for a transfer fee of £1.5m. He is a patron of the Manchester United Supporters' Trust (formerly Shareholders United).
On 27 August 2007, Solskjær announced his retirement from football after failing to recover from a serious knee injury. However, Solskjær remained at Old Trafford in a coaching role, as well as in an ambassadorial capacity. On 20 May 2008, Solskjær was announced as Manchester United's first full-time Reserve team manager since 2006, taking over from Brian McClair and Jimmy Ryan, who had filled the role in a caretaker capacity.
In November 2007 Solskjær was made a Knight, First Class of the Royal Norwegian Order of St Olav by King Harald V of Norway. He is to be presented with the award in a later ceremony in his hometown of Kristiansund. Solskjær is the youngest ever recipient of the knighthood, usually bestowed upon notable members of society in their later years.
For his commitment to Manchester United, Solskjaer was granted a testimonial which took place in the pre-season preparations for the 2008-09 season. The match was against Espanyol and was played on August 2nd. The game ended 1-0 to Manchester United, with the only goal coming from Fraizer Campbell shortly after the 80 minute mark. The testimonial gathered 68,868 spectators, the 2nd largest attendance for a testimonial in Great Britain, only beaten by Roy Keane's testimonial.
Solskjær scored 18 Premiership goals for United in his first season, helping United win the title in the last weeks of the season. The British media nicknamed him the "Baby-Faced Assassin" because of his youthful looks and his deadly finishing. He will perhaps be best remembered as a "super-sub", having earned wide acclaim for a remarkable habit of coming into matches late on as a substitute and scoring goals. Alex Ferguson remarked that Solskjær has a knack of sitting on the bench and studying the game without taking his eye off the action. One of his most impressive feats was coming off the bench to score four goals in the last twelve minutes of United's 8-1 thrashing of Nottingham Forest.
Solskjær stayed at Old Trafford even though other clubs showed interest in the player in 1998. The Norwegian went on to score the winning goal in the 1999 UEFA Champions League Final, helping the team secure the Treble and cementing his own place in the United folklore. These feats made him a favourite among the United supporters, inspiring songs such as "Who Put the Ball in the Germans' Net?" and "You Are My Solskjær". Although he had been absent on the pitch for a long time due to injury, United fans still fill matches with chants sung in Solskjær's honour.
After a few years of playing in the role of super-sub, Solskjær got a chance as a starter in the 2001-02 season, paired up with striker Ruud van Nistelrooy. He took the opportunity with characteristic incisiveness, forcing Andrew Cole and Dwight Yorke onto the bench.
By 2002-03, after both Andrew Cole and Dwight Yorke had left Old Trafford, Solskjær had only Diego Forlán and Van Nistelrooy to compete with for a place in the starting line-up. Still, Ferguson's persistence in playing van Nistelrooy up front as a lone striker meant that opportunities were limited.
Solskjær was subsequently given his time again when David Beckham picked up an injury and Ferguson played the Norwegian on the right wing. While proving himself to be an able crosser of the ball, Solskjær also popped up with goals, scoring a total of 16 goals for the season. He was selected to play on the right in important matches, such as in the league game against Arsenal and the Champions League quarter-final against Real Madrid, while Beckham was left on the bench. He also captained the team in a number of matches.
To show their continuing support, fans added a banner to the collection that lines the Stretford End reading "20 LEGEND (Solskjær wore number 20 for United). Solskjær further solidified his status amongst United fans when he became a patron of the supporters action group, Manchester United Supporters Trust (MUST), previously Shareholders United.
Solskjær returned to Premiership action in 23 August 2006 when he scored in an away match against Charlton Athletic, his first Premiership goal since April 2003. Ferguson commented after the match that "it was a great moment for Ole, United fans everywhere, the players and the staff" and that "Ole has been through a torrid time with injuries for the last two years, but he's persevered and never lost faith and has got his repayment tonight. Everyone is over the moon for him." He continued his come-back by putting in the winning goal in the Champions League clash with Celtic on September 13, fulfilling his post-injury ambition to score another goal at Old Trafford. Solskjær's first Premiership goal at Old Trafford since the return came on October 1 when he netted both goals in the 2-0 win against Newcastle. His goalscoring form continued with when he started the away match against Wigan Athletic and struck a sublime finish to round off a 3-1 victory, and again against Crewe Alexandra, on October 25, 2006, scoring the first of the 2-1 victory. After a further injury sustained in Copenhagen, Solskjær again returned on form scoring the third goal in the 3-1 win over Wigan on Boxing Day. Solskjær continued his form by scoring United's opening goal in their 3-2 win over Reading on the 30th of December. Additionally, he came on as a substitute to score an injury-time winner in the 2-1 victory over Aston Villa in the 3rd Round of the FA Cup on 7 January 2007.
After a match against Reading, Solskjær had further surgery on his knee. However, it was not as serious as his previous operations, and he was put out of action for only a month. He was predicted to be available for the 31 March game against Blackburn. United boss Alex Ferguson said: "It was good timing with the international break coming up. It gave us the opportunity to get the thing done." Solskjær did make his comeback from injury against Blackburn Rovers as a late substitute, and even scored in the 89th minute to seal Manchester United's 4-1 win.
On 5 June 2007, it was announced that Solskjær had undergone minor surgery after he reported discomfort in his knee while training with Norway. The surgery was a success, but Solskjær failed to fully recover and announced his retirement from professional football on 27 August 2007.
Since his retirement, there have been calls from football fans that Sir Alex Ferguson should retire the number 20 shirt as a tribute to Solskjær.
On 2 September 2006, Solskjær scored his first goal for the national team after his injury, when he scored the first and last goals in a 4-1 win against Hungary in a Euro 2008 qualifying match. It was also his first post-injury professional match where he played the full game.
On 19 April 2007, Solskjær stated that he could not see himself playing professional football past his contract expiry date, at the end of the 2008 season. He has already been granted a testimonial following his long service to the club—and in recognition of his popularity with supporters. The match took place on August 2nd 2008, a 1-0 win over RCD Espanyol. Solskjaer played the final 25 minutes of the match, coming close to scoring on two occasions.
In an interview in July covered on ManUtd.com, Solskjær refused to put a timescale on his professional career, but he was confident he would play out the one year left in his contract at Manchester United. He said, "The knee will never be 100 percent again, but as long as it doesn't hurt I'll continue to play. I don't know how long I can continue. It might be over after this season or I might be able to play another season." When interviewed by Setanta Sports in August 2007, Solskjær confirmed he would train to be a coach after retiring from professional football, and would start to earn the required badges after his last season with Manchester United. He also stated that unless his knee returned to a better state by the end of the 2007-08 season, that would definitely be his last season.
On 27 August 2007, it was announced that Solskjær had retired from football with immediate effect due to his ongoing knee injury. Finally, on September 4 at the home game against Sunderland, his retirement was officially announced over the Old Trafford tannoy, with Solskjær walking onto the pitch to a standing ovation. As of his retirement, Solskjær holds the record for the most goals scored for Manchester United as a substitute, scoring 28 goals off the bench.
|1||26 November 1995||Kingston||1-1||Draw||Friendly|
|2||27 March 1996||Windsor Park, Belfast||2-0||Win||Friendly|
|3||2 June 1996||Ullevaal Stadion, Oslo||5-0||Win||FIFA World Cup 1998 Qual.|
|5||30 April 1997||Ullevaal Stadion, Oslo||1-1||Draw||FIFA World Cup 1998 Qual.|
|6||25 March 1998||King Baudouin Stadium, Brüssel||2-2||Draw||Friendly|
|7||27 May 1998||Molde stadion, Molde||6-0||Win||Friendly|
|9||27 March 1999||Olympic Stadium (Athens)||2-0||Win||UEFA Euro 2000 Qual.|
|11||28 April 1999||Tblisi||4-1||Win||UEFA Euro 2000 Qual.|
|12||8 September 1999||Ullevaal Stadion, Oslo||4-0||Win||UEFA Euro 2000 Qual.|
|13||9 October 1999||Daugava Stadium, Riga||2-1||Win||UEFA Euro 2000 Qual.|
|14||27 May 2000||Ullevaal Stadion, Oslo||2-0||Win||Friendly|
|15||24 March 2001||Ullevaal Stadion, Oslo||2-3||Defeat||FIFA World Cup 2002 Qual.|
|16||28 March 2001||Minsk||1-2||Defeat||FIFA World Cup 2002 Qual.|
|17||15 August 2001||Ullevaal Stadion, Oslo||1-1||Draw||Friendly|
|18||14 May 2002||Ullevaal Stadion, Oslo||3-0||Win||Friendly|
|19||22 May 2002||Aspmyra stadium, Bodø||1-1||Draw||Friendly|
|20||2 April 2003||Luxembourg City||2-0||Win||UEFA Euro 2004 Qual.|
|21||11 June 2003||Ullevaal Stadion, Oslo||1-1||Draw||UEFA Euro 2004 Qual.|
|22||2 September 2006||Budapest||4-1||Win||UEFA Euro 2008 Qual.|