Faria started her career as a debater participating in a BTV debate show. She is a national debate champions in 2010 and 2011. She started her career in show business as a model in several television commercials. Throughout her career, she has worked in various television commercials and radio programs. In 2014, she hosted a reality show, Fair and Handsome: The Ultimate Man.

In 2015, she signed with Jaaz Multimedia to appear in two films, titled Aashiqui and Hero 420. The former, being her debut film, released in late 2015 while the latter released in early 2016. The former also earned Mazhar a Meril Prothom Alo Award for Best Newcomer in film or television. Both films were Indo-Bangladeshi joint ventures, being co-produced by Eskay Movies.

In 2016, Mazhar also starred in another Indo-Bangladeshi co-production, Badsha - The Don, directed by Baba Yadav. The film also starred popular Indian actor Jeet, and is considered a turning point in Mazhar's career, earning Mazhar a Tele Cine Award for Best Actress from Bangladesh.

After starring Indo-Bangladeshi films for the past two years, Mazhar then starred in two Bangladeshi films in 2017, Premi o Premi and Dhat Teri Ki. Mazhar also recorded dialogue for Detective, Bangladesh's first animated film. All three of these films were produced by Jaaz Multimedia and also starred Arifin Shuvo.

2017 also saw Mazhar return with the team behind Badsha - The Don for the film Boss 2: Back to Rule, again directed by Baba Yadav, produced by Jaaz Multimedia and starring Jeet. The film is a sequel to the 2013 film Boss: Born to Rule and also stars Subhasree Ganguly. The film is also an Indo-Bangladeshi joint venture, being co-produced by Walzen Media Works and Jeet's production company, Jeetz Filmworks. Initially rejecting the film, Mazhar later agreed to starring in the film when she read the script, describing her character as layered and an opportunity to show off her acting prowess, also calling the character a trendsetter. Mazhar also came under criticism for her costume in the music video for the song "Rj Rock" from Boss 2, a song which was also criticized for its lyrics. The actor tried her hand at singing for a music video, 'Pataka'. Written by Rakib Rahul, the song was composed by Pritom Hasan. The music video was highly criticised by the audience, getting larger number of dislikes than likes in YouTube.