Fahadh's first film, Kaiyethum Doorath (2002) was directed by his father, Director Fazil and failed at the box office. Fahadh later defended his father, stating "don't blame my father for my failure because it was my mistake and I came into acting without any preparation of my own". After his debut, he moved to the United States for five years, where he pursued his studies, before returning in 2009 to act in the film Kerala Cafe (2009), conceived by Director Ranjith. At Ranjith's behest, Director Uday Ananthan cast Fahad in his Mrityunjayam, one of the 10 shorts in the film. He played the role of a Journalist in the Mrityunjayam, a ghost film set on a spooky old 'Mana'. He was chosen to costar in B. Unnikrishnan's Pramani. He then appeared as a Business head in the thriller Cocktail (2010). His next film Tournament was also a thriller .

In June 2012, a case was registered against Fahadh by the Kochi Town Central Police for violation of the rule against public display of images of smoking. A poster of Diamond Necklace that showed him smoking a cigarette had been on display before the Kavitha Theatre in Kochi since the film was released.

His performance in Sameer Thahir's directorial debut Chappa Kurishu, a thriller in which he appeared as the head of a construction Business was much appreciated. "Arjun – my character in Chappa Kurishu is not a role that an actor gets often. I am very lucky and very fortunate," Fahad said. He shot a long kissing scene with his co-star Remya Nambeesan in the film — supposedly the first ever in Malayalam cinema — which upon release was termed controversial.

After the release of Annayum Rasoolum (2013), Fahadh Faasil openly declared to the media that he was in love with Actress Andrea Jeremiah. Andrea rejected reports that the pair were seeing each other. On 20 January 2014, he got engaged to Malayalam and Tamil film Actress Nazriya Nazim whom he married on 21 August 2014. The pair had gotten to know each other more on the sets of Anjali Menon's Bangalore Days (2014), in which they were playing husband and wife. Fahadh revealed that their parents had been pivotal in arranging the marriage.

In his next film, Lijin Jose's Friday, he acted as an auto rickshaw driver. The same year, he appeared in The Day of Judgement, one of the three featurettes from the portmanteau film D Company. His other films were Cinematographer Rajeev Ravi's directorial debut Annayum Rasoolum, Lijo Jose Pellissery's Amen, V. K. Prakash's Natholi Oru Cheriya Meenalla and Salam Bappu's directorial debut Red Wine. Amen was named as one of the best films of the year by Khaleej Times while Annayum Rasoolum managed to be a hit. In 2014, he acted in the big budget movie, Iyobinte Pusthakam which was produced by him. He also played a major role in the blockbuster movie Bangalore days. 2015 was a dull year for him as he was unable pull off a successful project. In 2016, his first release, Monsoon Mangoes failed at the box office, even though his performance was highly praised and the movie gathered good critic responses. His next release was on 5 February 2016 Maheshinte Prathikaaram which went on to become a blockbuster. It was highly applauded by both audience and critics.