Piku is a 2015 Indian Hindi-language comedy drama film directed by Shoojit Sircar and produced by N. P. Singh, Ronnie Lahiri and Sneha Rajani. Released in India on 8 May 2015, the film stars Amitabh Bachchan, Deepika Padukone and Irrfan Khan in titular roles, while Moushumi Chatterjee, Jisshu Sengupta and Raghubir Yadav appear in pivotal roles. The script was written by Juhi Chaturvedi while Anupam Roy composed the music and wrote the lyrics. Principal photography began in August 2014 and was wrapped up in December.

The film garnered critical acclaim, with praise for its screenplay, humour and overall simplicity, and particular praise directed towards the performances of Bachchan, Padukone and Khan. It also emerged as a commercial success worldwide. Made on a budget of ₹42 crore (equivalent to ₹63 crore or US$7.5 million in 2023), Piku earned ₹141 crore (equivalent to ₹213 crore or US$25 million in 2023) worldwide.

At the 61st Filmfare Awards, Piku received 8 nominations, including Best Film, Best Director (Sircar), and Best Actor (Bachchan) and won 5 awards, including Best Actress (Padukone). Bachchan won his record-setting fourth National Film Award for Best Actor at the 63rd National Film Awards and his record-setting third Filmfare Award for Best Actor (Critics) for his performance in the film.

Piku Banerjee (Deepika Padukone) is a 30-year-old Bengali architect who resides in Chittaranjan Park, Delhi along with her 70-year-old widowed father, Bhashkor Banerjee (Amitabh Bachchan). The hypochondriac Bhashkor has problems with chronic constipation and traces the root of every problem to his bowel movements. His habits often lead to arguments between Piku, the servants and Piku's maternal aunt, Chhobi Mashi (Moushumi Chatterjee), who often visits them. Piku loves her father and, as her mother has died, takes good care of him, but at the same time, also gets extremely irritated with him because of his eccentricities. Bhashkor has several medical tests done, but everything comes out to be normal, severely disappointing him. Ignoring Piku's vehement objections, he has also recently fired the maid for stealing phenyl, a charge that the maid opposes, and this is the fifth maid that Bhashkor has fired in the last two months. Moreover, Bhashkor is also opposed to the institution of marriage and wants Piku to take care of him to satisfy her maternal urge. He states that marriage is a low IQ decision, and that he wanted Piku's late mother to be independent, but she wasted her life in the service of him. Bhashkor also criticises Chhobi Maashi for marrying thrice and states that her own daughter, Eisha (Rupsa Banerjee), was never a priority for her.

Piku's business partner, Sayyed Afroze (Jisshu Sengupta), is a good friend of taxi business owner Rana Chaudhary (Irrfan Khan), whose taxi Piku always uses to commute to her workplace, but is notorious for being a very difficult customer. Regularly stressed both by her work and by her father's finicky behaviour, Piku criticises the taxi drivers with excessive backseat driving, due to which they lose focus and cause several car crashes. As no taxi driver at Rana's company wants to take Piku's duty, Rana complains to Sayyed but Piku brushes both of them off, offended by Rana's rude nature, and tells Sayyed that she is taking a break from the office. When Piku goes for a date with Aniket (Akshay Oberoi), Bhashkor keeps interrupting her, claiming that he has a fever, and makes such a fuss that Piku has to call his regular doctor, Dr. Srivastava (Raghuvir Yadav), and talk about Bhashkor's feces texture and temperature, causing Aniket to lose all appetite. Bhashkor also has a bit too much to drink at Chhobi Mashi's marriage anniversary party and later dances at home, which results in his blood pressure dropping and him being put on oxygen therapy, leaving Piku distraught. Elsewhere, Rana has his own family problems with his widowed mother and sister. Rana's sister stole her mother-in-law's jewellery and gave it to her mother, due to which her husband abandoned her along with their baby.

Bhashkor's relative, Nabendu (Aniruddha Roy Chowdhury), arrives from Kolkata to secure his consent to sell their ancestral home named Champakunj there. Nabendu tells that a builder is interested in the land and is willing to pay top rates, but Bhashkor objects vehemently and decides to visit Kolkata to stop the deal. Piku has to comply in accompanying him, since she cannot let him travel alone after the recent health scare. Bhashkor cannot travel by aeroplane due to his breathing problem and even refuses to travel by train as he receives constipation due to all the rhythmic movement. Bhashkor decides to travel by road, so that he can stop wherever he wants for excretion and receive some blood circulation going in his body, but none of Rana's taxi drivers are willing to endure Piku or her father. Disappointed with the taxi company, Piku tries to book a flight to Kolkata, but Rana personally arrives at their home to take the family to Kolkata himself, without informing his mother and sister about the trip. Rana is puzzled when he finds loads of baggage being loaded onto the car along with a lavatory chair for Bhashkor.

During the road trip to Kolkata, the group encounters many incidents, including Rana on the verge of losing patience due to Bhashkor's fussy behaviour and his constipation. Piku finds a large knife in Rana's car trunk, and Bhashkor insists Rana to throw the knife away or else he would not travel by the car. Rana pleads that the knife was kept by drivers for their road traffic safety, but has to eventually compromise and throw the knife away. During discussion, Rana reveals that he is an engineer and had a job in civil construction in Saudi Arabia. However, he was made to work as security guard on the site, despite being offered a job as project manager. When Rana protested, he was fired and that is when he returned to India to manage his family business established by his late father. They spend the night at a hotel in Varanasi, where Rana shares a room with Piku and Bhashkor as all other rooms are full and he refuses to sleep in the car. The next morning, Bhashkor tries Indian toilet-style sitting upon Rana's suggestion, which does not seem to help either.

The group finally reaches Kolkata, where Bhashkor's younger brother and sister-in-law still reside in Champakunj, and Bhashkor asks Rana to stay for a day. Piku and Rana spend time with each other in the city and gradually grow close. Rana also subtly hints Piku to not sell Champakunj during a discussion. The next day, Rana leaves Kolkata after advising Bhashkor to stop his eccentricities which he eventually agrees to. Piku changes her mind and decides not to sell Champakunj. Meanwhile, Bhashkor's sudden desire for bicycling increases after Dr. Srivastava gives him the news of a Japanese bicyclist having died at the age of 99. Believing that he will also live a long life by doing so, Bhashkor ends up bicycling through a part of the city alone, leaving everyone tensed since Bhashkor did not inform anyone about it. When Bhashkor returns, Piku berates him for eating street food and for being irresponsible, but Bhashkor simply states that his constipation is cleared, and that he that needs to bicycle every day. He also remembers Rana having advised him to eat everything and not to be dependent on anyone. Piku is secretly happy but does not emote much.