Billu (Irrfan Khan) is a poor barber who lives with his wife Bindiya (Lara Dutta) and their two children, Gunja (Mitali Mayekar) and Ronak (Pratik Dalvi) in the village of Budbuda. He also spends time with his close friends Budbudiya (Rajpal Yadav) and Naubat Chacha (Asrani). Though struggling, Billu lives an uneventful life until Bollywood superstar Sahir Khan (Shah Rukh Khan) comes to the village for a film shoot.
Billu has mentioned to his family that he knows Sahir from the past but has never elaborated how he knows the star. When his children talk about their father's friendship with the star, word spreads throughout the village. Virtually overnight, Billu, who had previously been scorned by most due to his lowly state, becomes the center of attention. People who had spurned him only the week before now call him a close friend so that he will introduce them to Sahir. Billu refuses and downplays the friendship. Even so, the powerful businessman Sahukaar Daamchand (Om Puri) demands to see Sahir and offers Billu expensive gifts in order to gain such a meeting. When Billu consistently fails to introduce the people of the village to Sahir, his situation changes once again. He is accused of lying about his friendship and everyone – including his wife and children – begin to doubt his character and integrity. Rather than defend himself, Billu remains quiet about the nature of his and Sahir's friendship.
On Sahir's last day in the village, the star speaks at a local school. He tells the children about his own impoverished childhood when he had nothing but a special bond of friendship with another young boy, named Billu. It was Billu who had taken care of Sahir and eventually helped him travel to Mumbai City by giving him his gold earring where Sahir became a star. Billu, who is standing at the back of the event, leaves during the talk without revealing to Sahir that he is there. However the townspeople realized their error, and take Sahir to Billu's house. Billu's children come home and apologise to their father. Then, Sahir appears in his car and is reunited with Billu. In the end, Sahir must leave for another shoot but promises that his and Billu's friendship is reignited and will remain friends.
Director Priyadarshan cast Shah Rukh Khan and Lara Dutta in pivotal roles in the film. While these roles were initially offered to Akshay Kumar and Tabu, Kumar eventually opted out of the project as did Tabu. The director then offered Kumar's and Tabu's role to Shahrukh Khan and Amisha Patel respectively, and both of them agreed to do the film. Patel also opted out of the film and sources have indicated that Juhi Chawla was signed on for the role.
In April 2008, the director announced that he had cast Lara Dutta as Billu's wife. The cast began filming for the project on 8 April 2008 and according to Shahrukh Khan, "the film is a sweet story of friendship...quite similar to the bond shared between Krishna and Sudama". The film also features Kareena Kapoor, Priyanka Chopra and Deepika Padukone in item numbers with Shahrukh Khan. This is the second film which actress Deepika Padukone worked together with director Priyadarshan after the Tamil film Snegithiye which Deepika Padukone did a small role.Shah Rukh Khan as Sahir KhanIrrfan Khan as Bilas Rao Pardesi aka 'Billu'Lara Dutta as Bindiya, Billu's wifeOm Puri as Sahukaar DaamchandRajpal Yadav as Zallan Kumar (Budbudiya)Asrani as Naubat ChachaManoj Joshi as Damodar DubeyRasika Joshi as Principal GahalotNagesh BhonsleAtul ParchureMitali Mayakar as Gunja, Billu's daughterPratik Dalvi as Ronak (Duggu), Billu's sonRushabh Shah as Taro BapuPriyanka Chopra in "You Get Me Rocking & Reeling" as Sahir Khan's heroineKareena Kapoor in "Marjaani" as Sahir Khan's heroineDeepika Padukone in "Love Mera Hit Hit" as Sahir Khan's heroine
The movie received great critical acclaim and rave reviews.
Billu opened to good reviews. In reviewing the film, Derek Elley of Variety stated: "Bigtime Bollywood meets small-town India with quietly entertaining, finally moving results in Billu Barber. Simple tale of friendship cleverly manages to bring together superstar Shah Rukh Khan, in full-on pin-up mode, with Irfan Khan, who's developed into one of the industry's best character actors, in a movie that straddles both mainstream Hindi cinema and more specialty fare. Mid-February release, produced by Khan's own company, Red Chillies, won't approach the grosses of his last starrer, Rab Ne Bana Di Jodi, but is way more engaging on an emotional level". Lisa Tsering of The Hollywood Reporter states that Billu is a "Bollywood comedy about an unlikely friendship [that] is full of unexpected pleasures". Frank Lovece of Film Journal International describes the film as a "delight" and states, "What makes it work ... is that neither Billu nor his situation is played for laughs—his hardscrabble poverty isn't glossed over, and neither is his wife's longing for acceptance in the class-conscious village. And a climactic speech by Khan at a school gathering works fully well emotionally, despite a huge potential for hokiness—and incidentally provides concrete reason why real-life Khan, who's often starred in glowering action-hero roles, is a genuinely top-notch actor in addition to being a popular star". The Times of India gave the film three stars and describes it as "a moving ode to friendship and ordinariness". While CNN-IBN's Rajeev Masand gave the film two out of five stars, he stated that it "works smoothly as a simple, moral tale, its charm interrupted every time the director goes for broader, more 'commercial' appeal. But it's enjoyable and heart-felt too, and for that reason deserves to be watched". Shashi Baliga of the Hindustan Times said that, "Though the film has its share of stock characters, maudlin and over-the-top moments and sags in the latter half, there’s also good story-telling, some great acting, and a healthy dose of masala in the item numbers".
Released on 5 January 2009, the soundtrack for Billu has music by Pritam with lyrics from Gulzar, Neeraj Shridhar, Sayeed Quadri, Ashish Pandit and Mayur Puri. The song "Khudaya Khair" was recorded by playback singer Abhijeet Bhattacharya who has rendered his voice for Shahrukh Khan in many movies. However, due to the ongoing controversy between Abhijeet and SRK, the song was withdrawn. The song "Love Mera Hit Hit" was sampled by Serbian pop singer Anabela in her song "Igra Istine", by Serbian singer Dejan Stanković in his song "Kaligula" and by Macedonian singer Boki 13 in his song "Kaligula".
The film was originally titled Billu Barber, but salon and beauty parlour associations of Bandra raised objections by finding the word "Barber" derogatory. As head of the film's production company, Shah Rukh Khan eventually removed the word from the movie title and promotions, renaming the film Billu. He also invited 'The Hairdressers' Association of Mumbai members to the premier of the movie in order to assuage their protests.