Princess Louise may refer to:

Princess Louise of Saxe-Gotha-Altenburg (Louise Dorothea Pauline Charlotte Fredericka Auguste; 21 December 1800 – 30 August 1831) was the wife of Ernst I, Duke of Saxe-Coburg and Gotha and the mother of Duke Ernst II and Prince Albert, husband of Queen Victoria. She was the paternal grandmother of King Edward VII of the United Kingdom. She is also the paternal great-great-great grandmother of Elizabeth II.

Princess Louise was a sidewheel steamboat built in 1869. From 1869 to 1879 this ship was named Olympia. In 1879 the name was changed to Princess Louise, after Princess Louise, Duchess of Argyll, a daughter of Queen Victoria who was married to Marquess of Lorne (1845-1914), Governor General of Canada from 1878 to 1883. Princess Louise was the last sidewheeler to be operated commercially on the coast of British Columbia.

Princess Louise of Denmark (Louise Caroline Josephine Sophie Thyra Olga) (17 February 1875 – 4 April 1906) was a Danish princess, the third child and oldest daughter of Frederick VIII of Denmark and his wife, Princess Louise of Sweden and Norway.

Princess Louise Charlotte of Saxe-Altenburg (Marie Agnes Louise Charlotte; 11 August 1873 – 14 April 1953) was a German noblewoman. She was a princess of Saxe-Altenburg by birth and a princess of Anhalt by marriage.

The Princess Louise was a 331-foot steamship, named in honor of Louise, Princess Royal and Duchess of Fife, Queen Victoria's granddaughter. The ship was part of the Canadian Pacific Railway's "Princess" fleet, the coastal counterparts to CPR's "Empress" fleet of passenger liners which sailed on trans-Pacific and trans-Atlantic routes. The ships of the British Columbia Coast Steamships came to be called "pocket liners" because they offered on smaller vessels the superior class of service, splendid amenities and luxurious decor equal to great ocean liners.

Princess Louise of Thurn and Taxis (German: Luisa Mathilde Wilhelmine Marie Maximiliane, Prinzessin von Thurn und Taxis; 1 June 1859, Schloss Taxis, Dischingen, Kingdom of Württemberg – 20 June 1948, Sigmaringen, Germany )

The wedding dress of Princess Louise Margaret of Prussia was worn by her at her wedding to Prince Arthur, Duke of Connaught and Strathearn, at St. George's Chapel, Windsor, on 13 March 1879. Prince Arthur was the seventh child and third son of Queen Victoria and Prince Albert of Saxe-Coburg and Gotha.