Competing at the 2012 CIS Track and Field Championships held in Winnipeg, he contested an impressive four events: the 1000 m, 1500 m, the 4 × 400 m, and the 4 x 800 m. Individually he earned podium finishes in the 1000 m and 1500 m, placing 3rd and 2nd respectively.

Later that summer, Charles made his international debut, representing Canada at the NACAC U23 Championships in Iraputo, Mexico.

In summer 2013, Charles placed 5th at the Canadian Championships and ran a personal best of 3:40.57 over 1500 m at the Victoria International Track Classic.

On May 15, Philibert-Thiboutot opened his outdoor season with a personal best of 3:38.55 in Los Angeles, breaking the 3:40 barrier for the first time.

At the 2014 CIS Cross Country Championships, Philibert-Thiboutot replicated his finish from the previous year placing 3rd over a challenging 10 km course in St. John's.

Charles opened his 2015 outdoor season at the Payton Jordan Invitational running 3:42.72 over 1500 m. On June 11 he competed in his first ever Diamond League meeting, contesting the Dream Mile at the Bislett Games in Oslo.

Competed at the Monaco Diamond League, Charles ran a 4 second 1500 m personal best clocking a time of 3:34.23, achieving the World Championship and Olympic qualifying standards in the process.

In 2016, Philibert-Thiboutot signed a five-year extension to his professional contract with Asics having already been sponsored by the company throughout his university career.

Despite suffering from achilles tendon issues,[6] Philibert-Thiboutot defended his Canadian title in Ottawa, running a time of 3:45.32 in the process.

On July 12, he ran his season's best 1500 m of 3:37.91 in Saint-Therese, Quebec, but missed the qualifying standard for the 2017 World Championships.

In his last attempt to hit the standard on July 22, just one day before the qualifying window closed, he ran 3:39.34 in Belgium, missing the mark by 3.94 seconds.

Heading into 2018, Charles still suffered from persistent achilles tendon issues but was able to open his outdoor season with a 3:37.73 1500 m in Prague on June 4.

He also represented the Americas at what would be the final edition of the IAAF Continental Cup, placing 4th in a time of 3:40.90 As a result of stress fracture in his foot, Philibert-Thiboutot only raced once in 2019, a 13:30.79 5000 m at Boston University on December 7.

In February 2021, Charles announced he had switched sponsors, ending his previous contract with Asics and signing with New Balance.

He won a bronze medal behind Americans Johnny Gregorek and Eric Holt, repeating his performance from the 2018 edition of the event.

On 18 June, once again in France, but this time in Tomblaine, he hit the Olympic standard, running 3:32.94, his second personal best in just 9 days.

As the two men rounded the final bend, Lumb was able to take the lead and win the race in a championship record of 3:37.24, while Charles finished close behind in 3:38.01.

He finished 7th over the 10 km course in Ottawa, earning the team title alongside his training partners from the Club D'athlétisme de 'Université Laval.

[10] Philibert-Thiboutot's 2024 season opener came on 26 January, contesting the mile at the Boston University John Thomas Terrier Classic.

However on the back stretch, NAU sophomore Colin Sahlman started to reel him in and with 50 metres to go passed Philibert-Thiboutot.

CPT held on to take second in 3:53.41, a personal best and under the World Indoor Championships qualifying standard of 3:53.50 for the mile.