Henrik Johan Ibsen (/ˈɪbsən/; 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.

Henrik Johan Ibsen was born on 20 March 1828 into an affluent merchant family in the prosperous port town of Skien in the county of Bratsberg (Telemark). He was the son of the merchant Knud Plesner Ibsen (1797–1877) and Marichen Cornelia Martine Altenburg (1799–1869), and he grew up as a member of the extended Paus family, which consisted of the siblings Ole and Hedevig Paus and their tightly knit families. Ibsen's ancestors were primarily merchants and shipowners in cities such as Skien and Bergen, or members of the "aristocracy of officials" of Upper Telemark, the region's civil servant elite. Jørgen Haave writes that Ibsen "had strong family ties to the families who had held power and wealth in Telemark since the mid-1500s." Henrik Ibsen himself wrote that "my parents were members on both sides of the most respected families in Skien", and that he was closely related to "just about all the patrician families who then dominated the place and its surroundings." He was baptised at home in the Lutheran state church—membership of which was mandatory—on 28 March and the baptism was confirmed in Christian's Church [no] on 19 June. When Ibsen was born, Skien had for centuries been one of Norway's most important and internationally oriented cities, and a centre of seafaring, timber exports and early industrialization that had made Norway the developed and prosperous part of Denmark–Norway.

Ibsen's parents, Knud and Marichen, grew up as close relatives, sometimes referred to as "near-siblings," and both belonged to the tightly intertwined Paus family of Rising and Altenburg House – that is, the extended family of the sibling pair Ole Paus (1766–1855) and Hedevig Paus (1763–1848).

After Knud's father Henrich Johan Ibsen (1765–1797) died at sea when Knud was a newborn, his mother Johanne Plesner (1770–1847) married captain Ole Paus (1766–1855) the following year. Like Henrich Johan Ibsen before him, Paus thus became the brother-in-law of Skien's wealthiest man, Diderik von Cappelen. In 1799, Ole Paus sold the Ibsen House in Skien's Løvestrædet (Lion's Street), which he had inherited from his wife's first husband, and bought the estate Rising outside Skien from a sister of his brother-in-law von Cappelen. Knud grew up at Rising with most of his many half-siblings, among them the later governor Christian Cornelius Paus and the shipowner Christopher Blom Paus. In the 1801 census the Paus family of Rising had seven servants.

Marichen grew up in the stately Altenburg House in the center of Skien with her parents Hedevig Paus and Johan Andreas Altenburg. Altenburg was a shipowner, timber merchant, and owned a large liquor distillery at Lundetangen and a farm outside of town, and after his death, Hedevig took over the business in 1824.

The siblings Ole and Hedevig Paus were born in Lårdal in Upper Telemark, where the Paus family belonged to the region's elite, the "aristocracy of officials," and had moved to Skien at a young age with their oldest sister, joining Skien's merchant elite with the support of their relatives in the family Blom. The children from Ole's and Hedevig's homes maintained close contact throughout Knud's and Marichen's childhood; notably, Ole's oldest son, Knud's half-brother Henrik Johan Paus, was raised in Hedevig's home. The Paus family reflects a meritocratic elite defined by education, priesthood, and public office.