Henrik Johan Ibsen (; Norwegian: [ˈhɛ̀nrɪk ˈɪ̀psn̩]; 20 March 1828 – 23 May 1906) was a Norwegian playwright. He is considered one of the world's pre-eminent writers of the 19th century and is often referred to as "the father of modern drama." He pioneered theatrical realism but also wrote lyrical epic works. His major works include Brand, Peer Gynt, Emperor and Galilean, A Doll's House, Ghosts, An Enemy of the People, The Wild Duck, Rosmersholm, Hedda Gabler, The Master Builder, and When We Dead Awaken. Ibsen is the most frequently performed dramatist in the world after Shakespeare. Store norske leksikon describes him as "the center of the Norwegian literary canon."

Ibsen was born into the merchant elite of the port town of Skien and had strong family ties to the Paus family and other families who had held power and wealth in Telemark since the mid-1500s. He established himself as a theater director in Norway during the 1850s and gained international recognition as a playwright with the plays Brand and Peer Gynt in the 1860s. From 1864, he lived for 27 years in Italy and Germany, primarily in Rome, Dresden, and Munich, making only brief visits to Norway, before moving to Christiania (Oslo) in 1891. Most of Ibsen's plays are set in Norway, often in bourgeois environments and places reminiscent of Skien, and he frequently drew inspiration from family members. Ibsen's early verse play Peer Gynt has strong surreal elements. After Peer Gynt Ibsen abandoned verse and wrote in realistic prose. Several of his later dramas were considered scandalous to many of his era, when European theatre was expected to model strict morals of family life and propriety. Ibsen's later work examined the realities that lay behind the façades, revealing much that was disquieting to a number of his contemporaries. He had a critical eye and conducted a free inquiry into the conditions of life and issues of morality. Critics frequently rate The Wild Duck and Rosmersholm as Ibsen's best works; the playwright himself regarded Emperor and Galilean as his masterpiece.

Ibsen is considered one of the most important playwrights in the history of world literature and is widely regarded as the foremost playwright of the nineteenth century. Sigmund Freud considered him on par with Shakespeare and Sophocles, while George Bernard Shaw argued that Ibsen had surpassed Shakespeare as the world's pre-eminent dramatist. Ibsen influenced other playwrights and novelists such as George Bernard Shaw, Oscar Wilde, and James Joyce. Considered a profound poetic dramatist, he is widely regarded as the most important playwright since Shakespeare. Ibsen is commonly described as the most famous Norwegian internationally. Ibsen wrote his plays in Dano-Norwegian, and they were published by the Danish publisher Gyldendal. He was the father of Prime Minister Sigurd Ibsen and a relative of the singer Ole Paus.