When Pascal was four, his mother (a nurse) and older brother (Nicholson Poulard) had left Haiti and settled in Laval, Quebec, just outside Montreal.

According to an interview from May 2005, Pascal's idol was Roy Jones Jr.[2] He represented Canada as a middleweight at the 2004 Olympics in Athens and won the gold medal at the Commonwealth Games in Manchester in 2002, against Paul Smith.

After the loss, Pascal fought Pablo Daniel Zamora Nievas on 4 April 2009 and won the fight by knockout in the fifth round to win the vacant WBO Inter-Continental super-middleweight title.

Pascal dominated the early action and worked well in the middle rounds but seemed to tire late and get frequently caught by the favored Dawson.

Pascal won the fight by a technical decision part way through the eleventh round due to an accidental head butt that caused a major cut over Dawson's right eye and was stopped by the ring-side doctor.

[14][15] Following Pascal's upset of Chad Dawson, 45-year-old Bernard Hopkins was soon named his next opponent for him to defend his WBC, Lineal, and The Ring light-heavyweight titles.

However, when Hopkins was asked about a potential rematch, he replaced most definitely only to claim that he was "too dangerous for anybody" and then went on to complain that GYM promotions was dragging the fight out to make him older so that he would lose.

[23] The fight was rescheduled for 18 January 2014 due to an injury that required surgery to remove bone fragments from Bute's left hand.

[30] On 29 May, it was announced that Pascal would fight on the Kovalev vs. Mohammedi undercard at the Mandalay Bay Events Center in Nevada on 25 July against undefeated Cuban prospect Yunieski Gonzalez (16–0, 12 KOs).

[32][33] On 5 December 2015 it was announced that the rematch between Kovalev and Pascal was set, to take place on 30 January 2016 at the Bell Centre in Montreal on HBO.

Kovalev won when Pascal's trainer Freddie Roach refused to let his fighter continue after the seventh round.

[36] Pascal announced he would fight on 16 December 2016 against 33 year old journeyman Ricardo Marcelo Ramallo at the Cogeco Amphitheater in Trois-Rivières.

Ramallo challenged for the vacant IBO International super middleweight title in 2015 in a losing attempt to Renold Quinlan.

It was confirmed that Pascal would main event the card against Egyptian contender Ahmed Elbiali (16–0, 13 KOs), with former world champion Chad Dawson appearing as chief support, however he pulled out of his fight.

[48][49] The Montreal Journal and TVA Sports reported on 7 May 2018 that Pascal, despite announcing his retirement in 2017, would return to the ring on the Adonis Stevenson vs. Badou Jack undercard on 19 May in Toronto.

[50] On 9 May, it was announced that Pascal would fight 36 year old former mixed martial arts fighter and hockey enforcer Steve Bossé on 29 June 2018.

[53][54] On 23 September, Groupe Yvon Michel announced that he had reached a deal for Pascal to fight Canadian cruiserweight champion Gary Kopas (10–11–2, 5 KOs) in Sydney, Nova Scotia on 9 November 2018 in a 12-round bout.

[55] The fight with Kopas was cancelled in early October after Sainvoyis Pascal, Jean's father, suffered a heart attack and died.

On 16 October, it was reported that Pascal was on the verge of returning to light heavyweight to challenge WBA champion Dmitry Bivol (14–0, 11 KOs) at the Etess Arena in Atlantic City on 24 November 2018.

It was rumoured that Pascal would challenge WBA interim light heavyweight champion Marcus Browne (23-0, 16 KOs), who was coming off a career-best win over Badou Jack in January.

[64] A few weeks later, the Pascal-Browne bout was moved to the Barclays Center in Brooklyn on the undercard of Adam Kownacki vs. Chris Arreola, with the event now being televised by FOX.

This gave Pascal a lead of 75–74 on all three judges' scorecards at the time of the stoppage in the middle of the eighth round, when the fight was halted due to a clash of heads.

[79] Pascal planned to take another fight before the year end, possibly a stay-busy whilst waiting for Browne to make a recovery.

[80] On October 25, 2019 it was announced that Pascal would defend his WBA (Regular) title against former two-division world champion Badou Jack on December 28 at State Farm Arena in Atlanta on the undercard of Gervonta Davis vs. Yuriorkis Gamboa.

However, Jack found his way back into the fight, using his jab and body punches to render damage to his opponent and win rounds.

[92] Jack took stay busy fight on Triller Pay-Per-View, on the undercard of Mike Tyson vs. Roy Jones Jr. exhibition in November 2020.

[94] In April 2021, the rematch against announced to take place on the undercard of Floyd Mayweather Jr. vs. Logan Paul on 6 June 2021 on Showtime PPV at the Hard Rock Stadium in Miami Gardens, Florida.

He said, “Stephan is one of the best coaches I have worked with and I have no doubt that he will remain a staple in Quebec boxing for many years to come.”[105] On March 8, 2022 it was reported that 34 year old Chinese boxer Meng Fanlong (17-0, 10 KOs) had turned down a catchweight fight against former world champion Sergey Kovalev in order to fight Pascal on May 20 in Plant City, Florida, promoted Probox, for their inaugural event.

[110][111][112][113] On July 23, 2022 the IBF formally ordered Pascal and unbeaten British boxer Joshua Buatsi (16-0, 13 KOs) to start negotiations for an eliminator.

[128] On July 24, 2024 Montreal Gazette reported that Pascal would return to the ring against Terry Osias (13-0, 6 KOs) on September 21 at the Colisée de Laval.