Helsingør (/ˌhɛlsɪŋˈɜːr/ HEL-sing-UR, Danish: [helse̝ŋˈøɐ̯ˀ]; Swedish: Helsingör), classically known in English as Elsinore (/ˈɛlsɪnɔːr, ˌɛlsɪˈnɔːr/ EL-sin-or, -⁠OR), is a coastal city in northeastern Denmark. Helsingør Municipality had a population of 63,953 on 1 January 2025, making it the 23rd most populated municipality in Denmark.^{[circular reference]} Helsingør is located at the narrowest part of the Øresund strait and together with Helsingborg in Sweden, forms the northern reaches of the Øresund Region, centred on Copenhagen and Malmö. Helsingør is a ferry city with frequent departures with the HH Ferry route which connects Helsingør with Helsingborg, 4 km (2.5 mi) across the Øresund.

Its castle Kronborg was used by William Shakespeare as the setting for his play Hamlet.

The first part of the name, Hels, is believed to derive from the word hals 'neck; narrow strait', referring to the narrowest point of the Øresund (Øre Sound) between what is now Helsingør and Helsingborg in Sweden. The word Helsing supposedly means 'person/people who live by the neck' and ør corresponds to old Norse aurr 'gravel beach' and eyrr 'sandy or gravelly shore'. The city was first mentioned as Hælsingør and the people as Helsinger in King Valdemar the Victorious's Liber Census Daniæ from 1231 (not to be confused with the Helsings of Hälsingland in Sweden). Place names show that the Helsinger may have had their main fort at Helsingborg and a fortified landing place at Helsingør, to control the ferry route across the strait. The particularly 19th-century tradition to explain toponymies, place names, with features of the landscape does not necessarily exclude the much older tradition of reading place names as eponymous. Although an obscure legendary character, or several, Helsing is quite abundantly present in traces of lost legends in the Nordic countries.

Although probably not the first Helsing, one of the three sons of Gandalf Alfgeirsson (the antagonist of Halfdan the Black, who was father of King Harald Fairhair, the semi-legendary, historical first king of a feudalist Norway) is called Helsing. He was brother to Hake and Hysing Gandalfson. Also Helsinki in Finland and Hälsingland in Norrland, Sweden, refers to Helsing, as "the Land of the Helsing/Helsinger," which makes the landscape theory of the name of Helsingør less likely.

The city as it is known today was founded in the 1420s by Danish King Eric of Pomerania. He established the Sound Dues in 1429, which were a toll on the use of the Øresund. Although a different toll had existed before this one, the Sound Dues were paid in Helsingør, providing immense wealth to the city. With that income, the king built a castle named Krogen or Ørekrog on the extreme northeastern tip of the island of Zealand. The city expanded around the castle and envelops it today. Krogen was rebuilt and expanded in the 1570s by king Frederik II and renamed Kronborg. All ships had to stop in Helsingør to get their cargo taxed and pay a toll to the Danish Crown, which generated a significant income to the city, which in turn generated trade. The city's growing wealth further fuelled the growth of maritime transport through the Øresund Strait - from 1479 to 1581 the number of ships passing through the strait increased 6.5 times. In 1672, Helsingør had grown to be the third-largest town in Denmark. Up until the middle of the 19th century, Helsingør was among the largest cities in the country.

The Sound Dues were abolished in 1857 with the Copenhagen Convention in which all seafaring nations agreed to pay a one-time fee. The abolishment was a huge loss for the city and the following decades saw a slow growth in population.

The oldest known fortified building of Helsingør is Flynderborg, an early medieval fortress on a hill just south of the medieval city.

Around 1200, the first church, Saint Olaf's Church, was built.