1855 in architecture

The year 1855 in architecture involved some significant architectural events and new buildings.

• October 15 – The second of the Prussia Columns is inaugurated, on the 60th birthday of their instigator, King Frederick William IV of Prussia.

• The Palais de l'Industrie for the Exposition Universelle in Paris, France, mainly designed by the architect Jean-Marie-Victor Viel and the engineer Alexis Barrault.
• Église Saint-Eugène-Sainte-Cécile [fr] in Paris, designed by Louis-Auguste Boileau, is completed.
• Church of St John the Evangelist, Preston, Lancashire, England, designed by E. H. Shellard, is completed.
• The Old Stone Church (Cleveland, Ohio) in the United States, designed by Charles Heard and Simeon Porter.
• Church of Saint Bartholomew, Brugherio in Italy, rebuilt to the design of Giacomo Moraglia, is completed.
• St Mary's Cathedral, Killarney, Ireland (Roman Catholic), to the design of Augustus Pugin following his death.
• The Victoria Tower of the Palace of Westminster in London, England, as The King's Tower, designed by Charles Barry and Augustus Pugin.
• Neues Museum, Berlin, Prussia, designed by Friedrich August Stüler.
• The original Smithsonian Institution Building in Washington, D.C., to the 1846 design of James Renwick Jr.
• Fremantle Prison in Western Australia, opened.

• RIBA Royal Gold Medal – Jacques Ignace Hittorff.
• Grand Prix de Rome, architecture – Honoré Daumet.

• May 12 – Alfred Gelder, English architect and politician active in Kingston upon Hull (died 1941)
• November 24 – Thomas Sully, self-trained American architect (died 1939)

• January 5 – Mihály Pollack, Austrian-born Neoclassical architect working in Pest, Hungary (born 1773)
• March 3 – Robert Mills, American architect, designer of the Washington Monument (born 1781)
• March 11 – James Gillespie Graham, Scottish architect (born 1776)
• March 27 – Richard Cromwell Carpenter, English ecclesiastical architect (born 1812)
• September 12 – John McCurdy, Irish architect, official architect to Trinity College, Dublin (born 1824)
• December 20 – Thomas Cubitt, English master builder (born 1785)