The year 1899 in architecture involved some significant events.
- March 14 - Church of the Saviour, Baku in Azerbaijan, donated and designed by Adolf Eichler, is consecrated.
- April 2 - Maison du Peuple in Brussels, designed by Victor Horta is officially opened (since destroyed).
- July 20 - Park Row Building in New York City is completed and becomes the tallest building in the world. It holds this title until 1908.
- September 1 - The National Theatre (Oslo) opens in Norway.
- September 18 - Old City Hall in Toronto, Ontario, designed by E. J. Lennox, is inaugurated.
- October - Work begins on St Agatha's Church, Sparkbrook, Birmingham, England.
- October 6 - John Rylands Library in Manchester, England, designed by Basil Champneys, is inaugurated.
- December 15 - Glasgow School of Art opens its new building, the most notable work of Charles Rennie Mackintosh.
- Raffles Hotel, Singapore, designed by Regent Alfred John Bidwell of Swan and Maclaren, is completed.
- Café Museum in Vienna, with interior designed by Adolf Loos, is opened.
- Approximate date - The Saitta House in Dyker Heights, Brooklyn, New York, designed by John J. Petit, is completed. In 2007, it is listed on both the State and National Register of Historic Places.