The year 1786 in architecture involved some significant architectural events and new buildings.

Buildings and structures

Buildings completed

• Casa de Esteban de Luca, Buenos Aires, Argentina.^[1]
• Golghar, Patna, India, built by Captain John Garstin.^{[2] [3]}
• Henley Bridge, designed by William Hayward of Shrewsbury,^[4] who died before construction was completed.
• Schloss Bellevue in Berlin, Germany, designed by Michael Philipp Boumann.^[5]
• St. Catherine's Cathedral, Kherson, Ukraine, built by General Ivan Gannibal.^[6]

Awards

• Grand Prix de Rome, architecture: Charles Percier.

Births

• January 23 – Auguste de Montferrand, French Neoclassical architect who worked primarily in Russia (died 1858)
• May 7 – John Watts, Irish military architect (died 1873)

Deaths

• February 28 – John Gwynn, English architect and civil engineer (born 1713)
• October 20 – Humphrey Sturt, British architect (born c.1725)