The year 1751 in architecture involved some significant events.

• June 29 – Foundations of Santo Domingo convent in Buenos Aires, designed by Antonio Masella Turin (construction completed in 1805), are laid.

• Dresden Cathedral in Saxony, designed by Gaetano Chiaveri (construction begun in 1738), is completed.
• Church of St. Michael in Berg am Laim, Munich in Bavaria, designed by Johann Michael Fischer (construction begun in 1738), is completed.
• Pilgrimage Church of Maria Schnee, Aufhausen in Bavaria, designed by Johann Michael Fischer (construction begun in 1736), is completed.
• Crossmichael Parish Church in south west Scotland (construction begun in 1749) is completed.^[1]
• The Kalvária Banská Štiavnica calvary in the Kingdom of Hungary (construction begun in 1744) is completed.
• The Sunehri Masjid ("Golden Mosque") in the Red Fort of Old Delhi, India (construction begun in 1747) is completed.
• Second Old Ursuline Convent, New Orleans, designed by Ignace François Broutin (construction begun in 1745), is completed.
• Codrington Library at All Souls College, Oxford, designed by Nicholas Hawksmoor (construction begun in 1716), is completed.
• Prince William Mansion, Copenhagen, is completed.
• Dutch House at Kuskovo near Moscow, designed by Y. I. Kologrivov (construction begun in 1749), is completed.

• May 20 – Jonathan Williams, American military engineer (d. 1815)

• January 6 – Carl Marcus Tuscher, German-born Danish portrait painter, printmaker, architect and decorator (born 1705)
• February 8 – Nicola Salvi, Italian architect (b. 1697)
• February 19 – Richard Cassels, German-born architect working in Ireland (b. 1690)
• March 3 – Batty Langley, English garden designer and pioneer of Gothic Revival architecture (b. 1696)
• August 9 – Ignace François Broutin, French military officer and architect in Louisiana (b. 1690)
• December 18 – Kilian Ignaz Dientzenhofer, Bohemian baroque architect (b. 1689)