Louise of Great Britain (originally Louisa; 18 December [O.S. 7 December] 1724 – 19 December 1751) was Queen of Denmark and Norway from 1746 until her death, as the first wife of King Frederick V. She was the youngest surviving daughter of King George II of Great Britain and Caroline of Ansbach.

The marriage between Louise and Frederick V of Denmark was arranged solely for political reasons (King George's ministers wanted Danish support in disputes with Prussia). Although the marriage was arranged, the couple got along quite well, at least during the first years of marriage. Louisa, who encouraged performances by actors and musicians, was a popular figure at the Danish court even though she never exerted significant influence over her husband's decision-making.

Princess Louise was born as the fifth daughter and youngest child of the then Prince and Princess of Wales, on 18 December [O.S. 7 December] 1724, at Leicester House, Westminster, London. She was born ten years after her paternal grandfather, Elector George Louis of Hanover, had succeeded to the thrones of Great Britain and Ireland in 1714 as George I, and her father had become Prince of Wales and moved to London with his family. Her father had a strained relationship with his own father, and in 1717, after a quarrel, the King had banished his son from court. He had subsequently lived at Leicester House, a large aristocratic townhouse in Westminster, where a rival court grew up, and which became a frequent meeting place for his father's political opponents. It was here that Louise was born.

She was baptised "Louisa" at Leicester House on 22 December. Her godparents were her elder sister and two cousins: Princess Amelia of Great Britain, Princess Louisa Ulrika of Prussia (for whom Sarah Lennox, Duchess of Richmond and Lennox, stood proxy), and Frederick, Prince Royal of Prussia, later Frederick the Great (for whom Henry de Nassau d'Auverquerque, 1st Earl of Grantham, stood proxy).

Princess Louise's mother was pregnant 11 times, but lost four of the children, so Princess Louise had six older siblings who lived to adulthood. Of these, Louise lived only with the two youngest, Prince William and Princess Mary and their parents in Leicester House. They constituted the 'younger set', born in London, in contrast to the 'older set', born in Hanover, whom King George I had separated from their parents in 1717. Her favorite sister was Princess Mary, who later married Frederick II, Landgrave of Hesse-Kassel; The future marriages of the two sisters would become a basis for the many dynastic marriages between the Danish royal family and the House of Hesse-Kassel in the following generations.

On 11 June 1727, when Louise was two years old, her grandfather, George I, died, and her father ascended the throne as George II. The family subsequently moved to St James's Palace, the London residence of the British monarch. Here Louise grew up, spending holidays at her parents' summer residence, Richmond Lodge, located near the River Thames in Richmond. In 1737, when Louise was almost 13 years old, her mother, Queen Caroline, died, and she was then raised mainly by her older sister, Princess Caroline.

In 1743, a dynastic marriage was negotiated between Louise and Crown Prince Frederick of Denmark and Norway. The marriage was proposed by Great Britain for political reasons. At the time of the marriage, both France and Great Britain wished to make an alliance with Denmark-Norway, and being protestant, Great Britain had the advantage of being able to make a marriage alliance. The Danish government was in favor of the proposal, while Frederick's father, King Christian VI, was initially reluctant. But he was convinced, as he hoped the marriage would lead to British support for his, or his son's, claim to the throne of Sweden. On a more personal level, there were hopes that marriage would suppress the frequent drinking and debauched behaviour of the Crown Prince. As for the Crown Prince, after having been presented with a portrait of the princess and finding her appearance appealing, and having been told of her amiability, he declared himself willing to marry Louise, all the more so as he too could see that the political circumstances made the marriage desirable.

Thus, the marriage negotiations began during the year of 1743, and were successfully concluded within a few months on 14 September. On 19 October, the 18 year old Princess Louise left London and began her journey towards Copenhagen. The Lord Chamberlain ordered the provision of supplies for the Princess, including "sets of royal bedding, portmanteaus, a travelling tea equipage, and items for Mrs. Dives and the "Fubbs" yacht: all to an estimate of £503". She first sailed aboard the royal yacht HMY Fubbs to her father's German possession, the Electorate of Hanover, where on 10 November a proxy wedding ceremony was conducted in Hanover with her brother, the Duke of Cumberland, as the representative of the groom. After this, the entourages of Louise and Frederick met in the border city of Altona in the then Danish Duchy of Holstein, where Louise met her husband for the first time a week after the wedding. There her English retinue was exchanged for a Danish one, headed by her new chamberlain Carl Juel and her Chief Court Mistress Christiane Henriette Louise Juel. Louise and Frederick then travelled together to Copenhagen, where they held their official entry into the Danish capital on 11 December to great cheers from the population. That same day a second wedding ceremony with the groom present was held in the chapel of Christiansborg Palace, the recently completed principal residence of the Danish Monarchy in central Copenhagen. Just a week later, on 18 December 1743, Louise celebrated her 19th birthday. To celebrate the birthday of the new crown princess the German poet Johann Elias Schlegel wrote a cantata.