Mick Wadsworth made his managerial mark at Carlisle United before Gary Megson asked him to become Assistant Manager at Carrow Road in the early part of 1996. His three year reign is still regarded by the Cumbrian side as one of their most successful periods. Replacing David McCreedy, he took Carlisle to the Division Three play-offs in 1993/94. The following season, they won the Division Three championship accumulating 91 points. An appearance at Wembley also came although they lost 1-0 in the final of the Auto Windscreens Trophy final against Birmingham City. Carlisle quickly returned to Division Three, relegated at the end of the 1995/96 season.

Prior to taking charge at Carlisle, Wadsworth's career had almost entirely been spent in non-league football. He played for Gainsborough Trinity, Frickley Athletic and Mossley although 28 league appearances were made on the wing for Scunthorpe in 1976/77, scoring three goals. He later managed Matlock Town before embarking on a FA coaching qualification.

When Megson was replaced by Mike Walker the following June, Mick moved on to manage Third Division Scarborough. He was apparently 45 minutes away from being sacked on Saturday 5th October but Scarborough came from 2-0 down to win 3-2 at Cambridge with a spirited second half.

On 28th January 1999, Mick quit as Scarborough boss to take over the vacant manager's seat at Second Division strugglers Colchester United. One of his rivals for the post was Mike Walker. Mick has spent some of his summer helping former Bradford City star Cec Podd with coaching the national team of St Kitts. Colchester's relatively poor start to the 1999/2000 season saw Mick quit as the U's boss on 25th August 1999 to be replaced by his assistant Steve Whitton.

After a brief spell helping Steve Coppell at Crystal Palace, the Sun reported on 10th September 1999 that Mick would return to his native North East to join new Newcastle manager Bobby Robson as first team coach. He was highly regarded by Sir Bobby Robson who said on his eventual departure that Wadsworth was solid, reliable and a very competent coach. "''I sat next to Alex Ferguson last Saturday... and talked football and I think so much of Mick Wadsworth that if I had not been manager of Newcastle and I knew Alex has lost Steve McClaren to Middlesbrough, I would have recommended Alex take him on board." At the start of July 2001, Mick left Newcastle to join Southampton as Assistant Manager to new Saints boss Stuart Grey.

Saints' appalling start to the 2001/02 season led to Stuart and Mick being sacked and replaced by Gordon Strachan on 21st October 2001 following the 2-0 defeat to fellow strugglers West Ham. He has since been linked with the vacancies at Barnsley and Sheffield Wednesday although some reports suggest a solo venture, others suggest a partnership with Jim Smith or Stuart Gray again. In fact, Mick went the solo route, and was appointed manager of Oldham Athletic on 7th November 2001 to replace Andy Ritchie. However Mick was sacked at the end of May 2002 due to differences with the board over the direction of the club. He was replaced by former Northern Irish international Iain Dowie.

Mick didn't remain out of employment for long and was appointed as the new manager of Huddersfield on 1st July 2002 to replace the sacked Lou Macari. However Huddersfield have languished at the wrong end of the Division Two table. At one stage Wadsworth was sacked but was reinstated when the Terriers revealed that they could not afford to pay him compensation. Instead Mel Machin has been brought in as Assistant Manager to aid Wadsworth. On March 25th 2003, the Terriers came to the end of their tether with Wadsworth and sacked him with the club bottom of Division Two. Machin took over the management of the club for the remainder of the season.

On 10th November 2003, the BBC reported that Mick had been appointed coach of the Democratic Republic of Congo's national side. He flew to Kinshasa the previous week for talks about the DR Congo coaching job and told BBC Sport that he has agreed to take the job. DR Congo Football Association chairman, Mr K Kuorara also confirmed the appointment. "Mr Wadsworth will coach the team until after the Nations Cup," he said. Wadsworth said that he was looking forward to the challenge of coaching The Simbas. "From the moment I was contacted about the job it interested me greatly." Wadsworth has already set up arranging his build-up to the Nations Cup. "I intend to take up the post on 24 November and will then take a team of local-based players to South Africa for a couple of matches. We hope to go to Europe after that for two or three weeks to train and to get the European-based players together as well."

Asked if his sacking from Huddersfield would have any bearing on his ability to succeed with DR Congo, Wadsworth was insistent that he was the right man for the job. "The issues at Huddersfield were not really to do with me," he added. "It was more to do with a club that was bankrupt and players were not being paid. My record up to then, in 20 years of coaching, was very good and I also have plenty of experience in international coaching having been involved with the English FA for seven years."

Wadsworth scoured the European leagues for players of Congolese nationality but first choice striker Shabani Nonda of Monaco has a longterm knee injury. Newcastle reserve Lomana Tresor Lua Lua instead led the attack. Their opening game in the tournament saw them beaten 2-1 by Guinea with former Liverpool striker Titi Camara scoring for the opposition. The Congo ended up losing all three of their first round group clashes and Wadsworth was sacked.

In February 2003, he was linked with the managerial vacancy at Grimsby Town.In May 2004, it was reported that Portugeuse side Beira Mar had offered him a contract as manager for 2004/5 to replace their current manager, Antonio Sousa, who had announced that he would be leaving the club at the end of the season. Beira Mar's squad consists of many foreign players and Wadsworth's international experience and strong ties with Africa are just some of the reasons the club is pursuing him. Mick parted company with Beira Mar early in the 2004/5 season.

He returned to English football in January 2005 becoming Assistant Manager at Gary Peters' Shrewsbury. He quit Shrewsbury on 27th March 2006 stating that although he had been happy at Gay Meadow, he wanted another opportunity to be a manager.

Mick then did some scouting for ambitious Scottish side Gretna and was appointed their Director of Football in July 2007, working with new first team managerDavid Irons as Gretna prepare for thie first season in the Scottish Premier League. The club's financial difficulties in early 2008 saw them fail to play their staff and manager Davie Irons resigned on 19th February 2008 with Wadsworth taking charge of first team affairs. In March 2008, the club went into administration and had to field a number of youth team players in their match with Aberdeen which the Dons won 3-0. It is considered doubtful whether Gretna will complete the season

Wadsworth lost his job when Gretna went bankrupt and were demoted to the Scottish Third Division. After this demotion, the one remaining potential buyer withdrew their offer to buy the club. In the belief that Gretna has ceased to exist, they resigned their place in the Scottish Football League on 3rd June2008

He was appointed manager of Conference newcomers Chester City at the end of June 2009. He was sacked on 30th September 2009 with Chester having won just twice in 13 games under his leadership, and with a 25point deduction, look certain to be relegated from the Conference at the end of the season

Wadsworth joined Hartlepool as first team coach in the summer of 2010 and was appointed caretaker manager after Chris Turner quit on 19th August 2010. This was extended to the end of the 2010/11 season on 1st December 2010. "Mick will remain as first-team coach. His brief will be to secure League One status," said chairman Ken Hodcroft. "It will be at the end of this season that the club will prepare for the 2011/12 season."

Wadsworth was handed the permanent position in the summer of 2011 but was sacked on 6th December 2011 having lost six home games in a row. He was replaced by Neale Cooper.

In May 2013, he took charge of Ebac Northern League Division One club Celtic Nation who are based in Carlisle. But after five months and ten games, and with Celtic Nation sitting at the top of the table, Wadsworth resigned on 20th September 2013 citing a two hour 45 minute commute from his Yorkshire home as one of the reasons for quitting, along with missing the day-to-day work on the training ground as Celtic Nation are still a part-time club. Club chairman Steve Skinner said: “Mick has resigned with immediate effect but we have parted on good terms. There is no ill-feeling but it has come as a huge shock. The thought of someone else coming in hasn’t crossed my mind yet because I’m absolutely devastated."

On 18th October 2013, Wadsworth was appointed as temporary assistant manager at Sheffield United, to support interim manager Chris Morgan. He left when Nigel Clough was appointed manager.

On 20th May 2014, Wadsworth was appointed manager of Sheffield FC, the world's oldest football club who play in the Northern Premier Division One South. Wadsworth said; “I am delighted to be joining the club. It is a great set-up with ambitious plans to move up the football pyramid. I cannot wait to get started and make a difference.”

On 16th July 2015, Wadsworth joined Sheffield United's academy and will coach all age groups from under-14s upwards. He will also mentor staff. He left the Blades in August 2019.