Shortly after entering law school in 1989, he obtained a television role which brought him to the attention of a wider public: that of Julien, a young student who comes to study in Montreal, in a TV show called Chambres en ville (Rooms in Town).
He then became host of a daily radio show at the Montreal station CKOI in 1991. The year after he began hosting a television game show Que le meilleur gagne (May the Best Man Win), for five years. In 1995, he got the job of host on a late evening television talk-show Cha-ba-da.
Since 2001, he has hosted a weekly radio show on the national Radio-Canada network, as well as a series of television shows, such as Culture Choc and "Les Debrouillards", in French and English, and a variety show on the France channel.
He is now conducting the chœurs du nouveau monde (New World Choirs) which includes notably les petits chanteurs de Laval au Canada (The Little Singers of Laval), les voix boréales (Northern Voices), and before that, le Chœur Gospel de Laval (the Laval Gospel Choir), which included Marie-Christine Depestre (now singer for the show Generation Motown), Christian Lazarre, and Mirkessa Telsaint.
He presented his first variety show, Noir et Blanc (Black and White) to more than 400,000 spectators across Quebec and the rest of Canada. He also performed in New York in 2004. A unique feature of his show is the second half, in which he offers to sing and play on the piano any known song submitted randomly by the spectators.
At the end of 2004, he released his first album, from his show, called Gospel Live Noir et Blanc.
On October 16, 2006, he launched his album I Think of You, which sold 109,000 copies in its first week, making Charles the highest selling Canadian artist in a one-week period for the year 2006. It debuted at number 1 on the Nielsen SoundScan album chart. It sold 41,000 units in its second week, to bring it to a total of 150,000 units after two weeks. Charles sold more albums in 2006 than all other Canadian musicians except Nelly Furtado.
However, one of his next scheduled appearances in Ottawa, where audiences were required to pay, did not fare so well. According to reports in the Ottawa Sun, Doug Moore, the city's manager of Venture Properties, said that Gregory Charles' scheduled concert at the Ottawa SuperEx was cancelled due to poor ticket sales.
In the fall, he began hosting a CBC radio program, In the Key of Charles .
This album was certified 2x platinum in Canada in December 2006.