The year 1827 in architecture involved some significant architectural events and new buildings.

• Work begins on the Athenaeum Club, London, designed by Decimus Burton.^[1]

• Staatliche Münze Karlsruhe (Baden), designed by Friedrich Weinbrenner (died 1826).
• Sing-Akademie zu Berlin, designed by Carl Theodor Ottmer.
• Old Council House, Bristol (England), designed by Robert Smirke.
• Union Club and Royal College of Physicians, Trafalgar Square, London, designed by Robert Smirke.
• Fireproof Building, Charleston, South Carolina, designed by Robert Mills.
• Mills Building, South Carolina Lunatic Asylum, designed by Robert Mills.
• Naval Medical Center Portsmouth (Virginia), designed by John Haviland.
• Hospital Real de Inválidos Militares de Runa (Portugal).
• Partis College, Bath (England) (almshouses).
• Bank of Louisiana, New Orleans.
• London Colosseum (panorama), designed by Decimus Burton for Thomas Hornor.
• Tremont Theatre, Boston (Massachusetts), designed by Isaiah Rogers.
• Hamburg Stadt-Theater.
• Lapua Cathedral (Finland), designed by Carl Ludvig Engel.
• Holy Trinity Church, Helsinki (Finland), designed by Carl Ludvig Engel, dedicated.
• Christ Church Cathedral (Hartford, Connecticut), designed by Ithiel Town.
• Church of St Mary, Haggerston (London), designed by John Nash, consecrated.
• Yeshua Tova Synagogue, Bucharest (Romania).
• Passage Choiseul (arcade), Paris, designed by Francois Mazois and completed by Antoine Tavernier.
• Halkyn Castle (Wales) (residence), designed by John Buckler.
• Hart-Cluett Mansion, Troy, New York, probably by Martin Euclid Thomson.^[2]
• Beckford's Tower, near Bath (England) (folly), designed by Henry Goodridge for William Beckford.
• Godmanchester Chinese Bridge (England), designed by James Gallier.
• Ozimek Suspension Bridge (Poland), designed by Karl Schottelius.
• New stone Shillingford Bridge (across River Thames in England).
• Beam Aqueduct, Rolle Canal, north Devon (England), designed by James Green.

• Grand Prix de Rome, architecture: Théodore Labrouste.

• January 17 – Samuel Hartt Pook, American naval architect based in Boston (died 1901)
• February 9 – Luigi Fontana, Italian sculptor, painter and architect (died 1908)
• March 14 – George Frederick Bodley, English architect (died 1907)
• May 16 – Pierre Cuypers, Dutch architect associated with Amsterdam (died 1921)
• June 18 – William Hill, English architect associated with Leeds (died 1889)
• August 3 – John Williams Tobey, American architect, carpenter and builder (died 1909)
• September 19 – J. P. Seddon, English architect and designer (died 1906)
• October 15 – Friedrich Adler, German architect and archaeologist (died 1908)

• March 11 – John Pinch the elder, English architect associated with Bath, Somerset (born 1769)
• April 27 – John Foster, Sr., English architect, Senior Surveyor to the Corporation of Liverpool and dock engineer (born 1758)
• November 1 – Louis-François Cassas, French landscape painter, sculptor, architect, archaeologist and antiquary (born 1756; stroke)^[3]