Indian-born Manmohan Malhotra (Rishi Kapoor) re-located to London, England, established himself, returned to India, got married to Bebo (Nina Wadia), and after four years got a visa for her so that she could live with him. Shortly thereafter, she gave birth to Jasmeet (Katrina Kaif). Manmohan was always embarrassed by Bebo as she was fat and could not speak English. As a result, he always left her out of important occasions, while he socialised. Bebo did not want Jasmeet to end up like her, so she got her educated in an English school, encouraged to mingle with British friends, and Jasmeet was transformed into Jazz – a beautiful young woman, modern in looks, talk, habits, and heart.
Her father had set her to meet a young lad, Bobby Bedi (Ritesh Deshmukh), though the date turns out to be a disaster and Bobby rejects her. Manmohan thinks that it is impossible to get him an Indian son-in-law, although his friend, Parvez Khan (Javed Sheikh), is in a similar situation with his son, Imran (Upen Patel), who has a blonde girlfriend, Susan (Tiffany Mulheron). Manmohan takes his family for a tour in India and forces Jasmeet to marry Arjun Singh (Akshay Kumar) who does not know how to speak English.
On their return to London, Jasmeet announces that she is getting married to Charlie Brown (Clive Standen), who is well educated and has good friends and connections, even with Prince Charles. She refuses to recognise her marriage with Arjun as there is no proof of the wedding. When Jasmeet is introduced to the friends of the Brown family, she is subjected to condescension from them (references to snake charmers, Indian rope tricks, tandoori chicken and so on) as well as a quote from Winston Churchill: 'When we leave India, the country will be in the hands of goons'. Arjun then tells the gentleman about the achievements of India which includes about the derivation of English words from Sanskrit like 'Father' , 'Brother' , 'Trignometry' and 'Geometry'. During this period, Jazz becomes close with Arjun who still supports her. Charlie Brown then has a rugby match against the Indians and Arjun, which the English lose and Brown is verbally racist to the Indians. Imran is then asked by Susan's parents to leave Islam, become a Christian, change his name to Emmanuel or Ian, as well as provide written proof that his family is not associated with terrorists. The film ends on a happy note when Imran decides not to be a Christian and Susan is accepted by Imran's family; Jazz realises her love for Arjun, runs away from her wedding to Charlie Brown, and goes with Arjun back to India where they are seen riding Arjun's motorcycle. While they are on the motorcycle Arjun reveals that all along he knew how to speak English. They all live happily ever after.Akshay Kumar as Arjun Ballu Singh
Katrina Kaif as Jasmeet Malhotra Singh (Jazz)
Rishi Kapoor as Manmohan Malhotra
Nina Wadia as Bebo Malhotra
Clive Standen as Charles Brown (Charlie)
Upen Patel as Imran Khan
Javed Sheikh as Parvez Khan (Imran's father)
Tiffany Mulheron as Susan
Riteish Deshmukh as Bobby Bedi (guest appearance)
Gurpreet Ghuggi as the taxi driver (special appearance)
Vir Das as prospective groom no. 1
Kunal Kumar as prospective groom no. 2
Manpreet Banga as prospective groom no. 3
Priyanka Chopra was the original choice for the role of Jasmeet Malhotra Singh (Jazz). However, Salman Khan forced the director to replace her with his then girlfriend Katrina Kaif.
The reviews of the film were generally positive. Taran Adarsh of indiafm.com wrote, "Namastey London is addictive stuff. You watch it once, you wanna watch it again." Akshay Kumar received almost unanimous praise for his portrayal of Arjun Singh, with a critic saying "Kumar certainly leaves his mark throughout the flick. One of the coolest performances of the star." Adarsh said "One of his finest performances so far, Namastey London also marks the coming of age of an actor who was often dubbed as an action hero or a funster. Akshay not only wins the heart of Katrina on screen, he's sure to win the hearts of millions of moviegoers with a terrific portrayal in this film." On Katrina Kaif's performance he wrote, "she handles the complex part with remarkable ease. The pretty lass is only getting better with every film."
Namastey London opened to a good response and mainly picked up momentum after the second and third day of its release, a major reason being India's exit out of the 2007 Cricket World Cup. The film did extremely well in the northern parts of India especially in Punjab, Haryana, Rajasthan and Uttar Pradesh. It also did well in Mumbai and in the first week of its release collected ₹73,575,657. The film was received very well in other parts of the country. The success of the film ended a long spell of box office failures since the release of Salaam-e-Ishq: A Tribute to Love in January 2007. The film went on to gross ₹714,102,500 worldwide, making it one of the top hits of 2007.
The film was also successful overseas. It debuted at number 9 on the UK charts and similarly debuted within the top 20 in the United States and Australian charts. The film collected £238,841 in the first week of its release. As of 27 July 2007, the movie grossed an estimated $15,273,747 in five territories which included the United States ($4,149,772), Australia ($197,148), India ($17,267,662), Malaysia ($15,285), and the United Kingdom ($9,021,900).
The soundtrack album was released on 27 January 2007 and received good reviews. The songs were composed by Himesh Reshammiya. Salim-Sulaiman composed the film score. The song "Chakna Chakna" and its remix version were penned by Sameer, all other songs were penned by Javed Akhtar. According to the Indian trade website Box Office India, with around 14,00,000 units sold, this film's soundtrack album was the year's sixth highest-selling.
The film was unofficially remade in Bengali, as Paran Jai Jaliya Re starring Dev and Subhashree Ganguly. The Kolkata High Court in December 2009 banned the screening of the film for plagiarism after a petition was filed by the film's producers.
In March 2011, Shah announced his intention to make a sequel, Namastey England. Kumar and Sonakshi Sinha have been signed to play the leads in the sequel, which will shoot scenes in London, Punjab, Mumbai, Germany, and Switzerland. The film's plot has not been fully revealed, but it will not be a direct continuation of the first film.