The film features an ensemble cast led by Jessica Alba, Kathy Bates, Jessica Biel, Bradley Cooper, Eric Dane, Patrick Dempsey, Héctor Elizondo, Jamie Foxx, Jennifer Garner, Topher Grace, Anne Hathaway, Ashton Kutcher, Queen Latifah, Taylor Lautner, George Lopez, Shirley MacLaine, Emma Roberts, Julia Roberts, and Taylor Swift in her film acting debut.

Florist Reed Bennett (Ashton Kutcher) wakes up and proposes to his girlfriend Morley Clarkson (Jessica Alba), who accepts.

On a flight to Los Angeles, Kate Hazeltine (Julia Roberts), a captain in the U.S. Army on a one-day leave, befriends Holden Wilson (Bradley Cooper).

Julia, an elementary school teacher, has fallen in love with cardiothoracic surgeon Dr. Harrison Copeland (Patrick Dempsey), but does not know that he is married to Pamela.

Julia suggests to Edison to give the flowers to a girl named Rani in his class who has a crush on him after telling him the meaning of love.

Edison's babysitter Grace Smart (Emma Roberts) is planning to lose her virginity to her boyfriend Alex Franklin (Carter Jenkins).

Edison's grandparents, Edgar (Hector Elizondo) and Estelle Paddington (Shirley MacLaine) are facing the troubles of a long marriage.

Sean Jackson (Eric Dane), a closeted gay professional football player, is contemplating the end of his career with his publicist Kara Monahan (Jessica Biel) and his agent Paula Thomas (Queen Latifah).

Substituting for Paula's absent secretary is one of the firm's receptionists, Liz Curran (Anne Hathaway), who dates mailroom clerk Jason Morris (Topher Grace).

Edgar and Estelle reconcile and redo their marriage vows, Harrison's wife has left him because of his infidelity and Morley tries to call Reed, who is instead starting a new relationship with Julia.

In addition, amongst the plethora of brief cameo appearances, director Garry Marshall plays a violinist (his usual family crew of wife, son, daughter, grandchildren and niece also appear), singer Paul Williams provides opening and closing dialogue as a radio DJ, and ESPN sports journalist Hannah Storm plays herself.

Track listing for the score album: The film debuted in the US on February 12, 2010 with $52.4 million its opening weekend, grabbing the number 1 spot over the holiday that shares its name.

The website's consensus reads: "Eager to please and stuffed with stars, Valentine's Day squanders its premise with a frantic, episodic plot and an abundance of rom-com cliches.

"[8] Metacritic, which uses a weighted average, assigned the film a score of 34 out of 100, based on 33 critics, indicating "generally unfavorable" reviews.

[10] Giving the film three out of four stars, the overall opinion of Carrie Rickey's review for The Philadelphia Inquirer is that "It is a pleasant, undemanding movie that takes place over 18 hours on V-Day and considers Very Attractive People whose romantic destinies converge, diverge, and cloverleaf like the interstates threading through California's Southland".

[17] Valentine's Day is noted for sharing similarities with the British film Love Actually,[18][19][20][21] particularly the basic premise of multiple storylines occurring around a popular holiday, and sometimes identical subplots.