He first entered the top 16 in the 1995–96 world rankings and remained there continuously for over 29 years until September 2024, setting a record for the longest uninterrupted tenure as a top-16 player.

In 2010, a tabloid newspaper carried out a sting operation in Ukraine, in which it claimed to show Higgins and his then-manager arranging to lose specific frames in future matches for money.

His first time playing at the World Snooker Championship in 1995 he lost 3–10 in the first round to fellow Scottish player Alan McManus.

[12] At the 1996 UK Championship, he defeated Tony Drago, Williams and Doherty to reach the final, where he faced the world champion, Stephen Hendry.

[14][15] At the 1998 World Snooker Championship, Higgins defeated Jason Ferguson 10–8, Anthony Hamilton 13–9, John Parrott 13–11 and O'Sullivan 17–9 in the semi-finals.

O'Sullivan missed a red ball to a baulk pocket while on a break of 60, and Higgins made a clearance of 64 to win 10–9 and claim his second Masters title.

[38][39] At the 2007 World Snooker Championship, Higgins beat Michael Holt, Fergal O'Brien, O'Sullivan and Stephen Maguire en route to the final.

Trailing 10–14 against Maguire, Higgins won 17–15,[40] making the 1,000th century to be made at the Crucible Theatre, Sheffield since the World Championship was first staged there in 1977.

However, at 14–13, Higgins rediscovered his form to win four consecutive frames to clinch the match 18–13 to secure his second World title at 12:54 am, the latest finish to a World final (equalled when Neil Robertson beat Graeme Dott in 2010); and nine years after his first title – the longest time span between successes since Alex Higgins (1972, 1982) and the longest at the Crucible.

He won the Grand Prix for the fourth time in 2008,[48] beating Ryan Day 9–7 in the final in Glasgow – his first ranking tournament win on home soil.

His second-round and quarter-final matches both went the full distance of 25 frames, with Higgins overcoming Jamie Cope[50] and Mark Selby,[51] respectively, to win 13–12.

[62][63] On 2 May 2010, Higgins and his manager, Pat Mooney, a World Professional Billiards and Snooker Association (WPBSA) board member, were the subject of match-fixing allegations.

[67] A full investigation was conducted into the allegations by David Douglas, former Metropolitan Police detective chief superintendent and head of the WPBSA's disciplinary committee.

The independent tribunal that followed in September 2010, hosted by Sports Resolutions (UK) and chaired by Ian Mill QC, concurred that the WPBSA was right to conclude that Higgins had truthfully accounted for his words and actions and to withdraw the more serious charges of match-fixing, but found him guilty of "giving the impression" that he would breach betting rules and of failing to report the approach made to him by the News of the World.

[72] As a result of his progress in those three events, where he won 18 out of 19 matches, Higgins earned sufficient points to regain his position as world number one under the new two-year rolling ranking system after having slipped to third by missing the start of the 2010–11 snooker season.

[76] A little over two weeks later, Higgins successfully defended his Welsh Open title by beating Stephen Maguire 9–6 in the final[77] – dedicating victory to his late father.

[82] On the way to a 17–14 victory over Mark Williams in the semi-finals, Higgins was heckled by an audience member who shouted out, "How do you swallow that three hundred thousand, John?

[92] Higgins started the 2012–13 season by winning his 25th ranking title at the Shanghai Masters, after coming back from 2–7 down to defeat Judd Trump 10–9 in the final.

However, Higgins did not enjoy sustained success for the rest of the season, reaching only one other semi-final of a major ranking event, the World Open, which he lost 2–6 to Mark Allen.

[99] Playing with a new cue, he won the minor-ranking 2013 Bulgarian Open with a 4–1 victory over Neil Robertson in the final, having beaten Shaun Murphy and Ronnie O'Sullivan earlier in the event.

[110] After the UK Championship, he slipped to number 12 in the world rankings, having failed to progress beyond the last 16 of any tournament since the Wuxi Classic in June.

[140] Higgins started his quarter-final with Neil Robertson at the 2015 UK Championship by making the 600th century break of his career, but lost the match 5–6.

[144] He faced Stuart Bingham in the final of the inaugural China Championship; with the scores tied at 7–7, Higgins made three successive centuries to claim the title and £200,000, which was, at the time, the highest prize awarded outside the United Kingdom.

John froze me out from start to finish, he played an incredible match.”[164] Before the beginning of the 2021–22 snooker season, Higgins lost a significant amount of weight by taking spin classes.

[165] At the 2021 Northern Ireland Open, he won six consecutive frames to defeat Yan Bingtao 6–2 in the semi-finals, but lost the final 8–9 to Mark Allen, despite having led 8–6.

[174] Afterwards, Higgins admitted that losing the final from a position of being five frames up with six to play would leave "real mental scars".

[184] In 2006, Higgins was escorted off a plane for being drunk after losing the Malta Cup final to Ken Doherty, but he became teetotal in preparation for the 2007 World Championship which he went on to win.

[187] In February of that year, Higgins and his wife Denise appeared on ITV's Mr. and Mrs. and reached the final after answering all of their questions correctly to win £30,000.

They donated the money to The Dalziel Centre – a day hospice for cancer patients, based at Strathclyde Hospital in Motherwell, of which Higgins became a patron after they cared for his terminally ill father.

[188] In a complex mathematical study conducted at the University of Limerick, Higgins was named the highest performing snooker player from 1968 to 2020, ahead of Ronnie O'Sullivan, Mark Williams and Stephen Hendry.