Melançon started acting in 2003. She was at that time a successful model and was signed to Wilhelmina Modeling Agency. She appeared on "Legends of Tomorrow" as Masako Yamashiro in season 2. Melançon also appeared in the final season of The L Word as recurring character "Jamie Chen," as Psylocke in X-Men: The Last Stand, as "Miyu", Kevin Spacey's assistant in Shrink, as Lynda in the HK-shot film Irreversi, as Dr. Catherine Ivy in the psychological thriller/horror film Pathology with Milo Ventimiglia, and as the other "Girl in the Car" along with Maggie Q in Rush Hour 2 when she was still modeling. Melançon also starred as Lotus Long in the short film bio-pic Keye Luke, which premiered at the 2012 Los Angeles Asian Pacific Film Festival and which was Closing Night Film of the inaugural 2013 Seattle Asian American Film Festival. She starred in Blumenthal where she played Scottish actor Brian Cox's niece, and the film made its premiere in 2013 at the Santa Barbara International Film Festival.