The film begins with a voiceover from David (Hugh Grant) commenting that whenever he gets gloomy about the state of the world he thinks about the arrivals terminal at Heathrow Airport, and the pure uncomplicated love felt as friends and families welcome their arriving loved ones. David’s voiceover also relates that all the messages left by the people who died on the 9/11 planes were messages of love and not hate. The film then tells the ‘love stories’ of many people:
Billy Mack and Joe
With the help of his longtime manager Joe (Gregor Fisher), rock and roll legend Billy Mack (Bill Nighy) records a Christmas variation of The Troggs’ “Love Is All Around”. Although he thinks the record is terrible, Mack promotes the release in the hope it will become the Christmas number one single, which it does. After briefly celebrating his victory at a party hosted by Sir Elton John, Billy discerns that Joe is in need of affection and suggests that he and Joe celebrate Christmas by getting drunk and watching porn.
Juliet, Peter, and Mark
Juliet (Keira Knightley) and Peter’s (Chiwetel Ejiofor) marriage is videotaped by the best man, Mark (Andrew Lincoln). Although both Juliet and Peter believe that Mark dislikes Juliet, he is actually in love with her. When Mark evades Juliet’s requests to see the video he made at the wedding, she visits him. She says she wants them to be friends and, when she finds and views the wedding video, it turns out to be just adoring close-ups of her. After an uncomfortable silence, Mark blurts out that he snubs her out of “self-preservation.” On Christmas Eve, Juliet answers the doorbell to find Mark carrying a boombox playing Christmas songs and large cue cards, on which he has written, without expectation of reciprocation, that he loves her. As he walks away, Juliet runs after him to give him a quick kiss before she returns inside.
Jamie and Aurélia
Writer Jamie (Colin Firth) is pushed by his girlfriend (Sienna Guillory) to attend Juliet and Peter’s wedding alone, as she feigns illness. He returns between the ceremony and the reception to check on her, and discovers that she is having an affair with his brother. Crushed, Jamie withdraws to his French cottage, where he meets Portuguese housekeeper Aurélia (Lúcia Moniz), who does not speak English. Despite their inability to communicate, they become attracted to each other. When Jamie returns to England, he realises he is in love with Aurélia and begins learning Portuguese. He returns to France to find her and ends up walking through town, gathering people as they walk to her job at a restaurant. In broken Portuguese he declares his love for her and proposes. She says yes, in broken English, as the crowd erupts in applause.
Harry, Karen, and Mia
Harry (Alan Rickman) is the managing director of a design agency; Mia (Heike Makatsch) is his new secretary. Harry is comfortably married to Karen (Emma Thompson), who stays home to raise their children. He becomes increasingly aroused by Mia’s overtly sexual behaviour at the office and does nothing to dissuade her. At the company Christmas party held at Mark’s gallery, Harry not only enquires if Mark is Mia’s boyfriend, but also dances closely with her. While at the shops, he calls her to find out what she wants for Christmas and ends up almost caught by his wife purchasing an expensive necklace from the jewellery department thanks to the salesman Rufus (Rowan Atkinson). Later on, Karen discovers the necklace in Harry’s coat pocket and happily assumes it is a gift for her. When she finds a similarly shaped box under the tree to open on Christmas Eve, she is heartbroken to find it is a Joni Mitchell CD, meaning that the necklace was for someone else. She confronts Harry and asks him what he would do if he were her. She says that he has made a mockery of their marriage and of her.
David and Natalie
Karen’s brother, David (Hugh Grant), is the recently elected Prime Minister. Natalie (Martine McCutcheon) is a new junior member of the household staff at 10 Downing Street. During a meeting with the U.S. President (Billy Bob Thornton), they run into Natalie and the president makes some inappropriate comments to David about Natalie’s body. Later, David walks in on Natalie serving tea and biscuits to the president, and it appears that something untoward is happening. Natalie seems ashamed, but the president has a sly grin on his face. At the following joint press conference, David is uncharacteristically assertive while taking a stand against the president’s intimidating policies. Finding that his relationship with Natalie has become strained and a distraction, David has her moved to another job. However, he is spurred to action on Christmas Eve when he finds a Christmas card from Natalie declaring that she is his and no one else’s. After a door-to-door search of her street, he comes across Mia, who informs him that Natalie lives next door. The entire family is on their way to a multi-school Christmas play and he offers to drive them so he can talk to her. After Natalie sneaks him in to the school, he runs into his heartbroken sister, who believes he is there for his niece and nephew. As David and Natalie try to keep from being seen and watch the show from backstage, they finally kiss. All their hiding is for nothing, however, as the curtain rises and they are seen kissing by everyone.
Daniel, Sam, Joanna, and Carol
Daniel (Liam Neeson), Karen’s friend, mourns the recent death of his wife, Joanna, as he tries to raise his stepson Sam (Thomas Sangster) alone. Sam has fallen for an American classmate, also named Joanna (Olivia Olson), and, after discussion with his stepfather, decides to learn the drums so that he can accompany her in the big finale for their school’s Christmas pageant (the same one that David’s niece and nephew/Karen and Harry’s children are in). After Sam feels that he missed his chance to make an impression on her, Daniel convinces him that he must go catch Joanna, who is returning to the US, at the airport that night and show her how he feels, lest he regret it. Sam runs away from the airport security and says hi to Joanna, who then kisses him on the cheek. Meanwhile, Daniel meets Carol (Claudia Schiffer), the mother of one of Sam’s schoolmates.
Sarah, Karl, and Michael
Sarah (Laura Linney) first appears at Juliet and Peter’s wedding, sitting next to her friend Jamie. She is an American who works at Harry’s graphic design company and has been in love for years with the company’s creative director, Karl (Rodrigo Santoro). They finally connect at the firm’s Christmas party and he drives her home. As they kiss, Michael, her mentally ill brother, phones from a mental care facility. The evening tryst is aborted. Both are working late on Christmas Eve but Karl just wishes her a Merry Christmas. Michael calls Sarah and she joins him, sharing her Christmas scarf.
Colin, Tony, and the American girls
After unsuccessfully attempting to woo various English women, including Mia and Nancy (Julia Davis), the caterer at Juliet and Peter’s wedding, Colin Frissell (Kris Marshall) informs his friend Tony (Abdul Salis) that he plans to go to America, convinced that his Britishness will be an asset. Landing in Milwaukee, Wisconsin, Colin meets Stacey (Ivana Miličević), Jeannie (January Jones), and Carol-Anne (Elisha Cuthbert), three stunningly attractive women who fall for his Estuary English and invite him to stay at their home, where they are joined by roommate Harriet (Shannon Elizabeth).
John and Judy
John (Martin Freeman) and Judy (Joanna Page) are professional stand-ins for films. They meet for the sex scenes in a film for which Tony is a production assistant. John tells Judy that “It is nice to have someone [he] can just chat to.” While the two are perfectly comfortable being naked and simulating sex on-set, they are shy and tentative off-set. Carefully pursuing a relationship, they attend the Christmas pageant (involving David and Natalie, Harry and Karen’s children, Daniel and Sam, et al.) at the local school with John’s brother.
Rufus (Rowan Atkinson) is the jewellery salesman, whose obsessive attention to gift-wrapping nearly results in Harry being caught buying a necklace for Mia by Karen. Also, it is his distraction of staff at the airport which allows Sam to sneak through to see Joanna. In the director and cast commentary, it is revealed that Rufus was originally supposed to be a Christmas angel; however, this was dropped from the final script.
One month later, all of the characters are seen in Heathrow Airport. Billy tells Joe that his Christmas single has spurred a comeback. Juliet, Peter, and Mark meet Jamie and his bride, Aurélia. Karen and the kids greet Harry, but Karen’s reaction suggests that they are struggling to move past his indiscretion. Sam greets Joanna, who has returned with her mother from America, and Daniel is joined by his new girlfriend Carol and her son. Newlyweds John and Judy, heading off to their honeymoon, run into Tony, who is awaiting Colin as he returns from America. Colin returns with Harriet and her sister Carla (Denise Richards), who greets Tony with a hug and a kiss. Natalie welcomes David back from his flight in view of the press, indicating that their relationship is now public. These scenes dissolve into footage of actual arrivals at Heathrow, as the screen is divided into an increasing number of smaller segments which form the shape of a heart.
All the stories are linked in some way, with the exception of Billy Mack and his manager, who are not acquainted with any of the other characters, but Billy appears frequently on characters’ radios and TVs, his music video twice providing an important plot device for Sam’s pursuit of Joanna; the pair also cross paths with the other characters in the closing Heathrow scene. John and Judy work with Tony, who is best friends with Colin, who works for a catering company that services the office where Sarah, Karl, Mia, and Harry work. Mia is friends with Mark, who runs the art gallery where the Christmas office party takes place. Mia also lives next door to Natalie. Mark is in love with Juliet and friends with Peter. The couple are friends with Jamie and Sarah. Harry is married to Karen, who is friends with Daniel, and Karen’s brother is David, who works with Natalie. Harry and Karen’s children (and thus David’s niece and nephew), Natalie’s siblings (and thus Mia’s neighbours), and Carol’s son are all schoolmates of Sam and Joanna. An additional plot that was dropped in editing concerned the children’s headmistress (Anne Reid) and her dying lesbian partner (Frances de la Tour).