Joseph Stiller von Stillburg (August 24, 1847 – December 23, 1923) was an Austrian-American architect in Pittsburgh, Pennsylvania.
Stillburg was born in the Austrian Empire to Joseph Stillburg Sr. and Marie Berchschnieder. He served in the Austrian Army during the Austro-Prussian War in 1866, where he survived a deadly cholera outbreak while stationed in Trieste. The soldiers were forbidden from drinking water or eating fruit and vegetables, and survived on red wine.
He immigrated to the United States in 1868 and married Amelia. He had at least three sons: Frederick Albert (1885–1952), Osker (born 1887) and Albert James (1893–1977). Frederick apparently suffered from mental illness; in 1937s he was homeless and arrested in Los Angeles after causing a scene in which he declared himself to be Kaiser of Austria and the King of Hungary.
His work includes the Winter Garden at Exposition Hall. He also designed the Eberhardt & Ober Brewery (Penn Brewery and Brewery Innovation Center) and Troy Hill Fire Station #39 (1901). He is also credited as the architect of the Suibertus G. Mollinger / St. Anthony of Padua Shrine.Frederick J. Osterling trained in his office.
Stillburg's best known work, however, is the Administration Building at Seton Hill University. Completed in 1889, the building was constructed with Pittsburgh brick and Ohio sandstone and was designed for the St. Joseph Academy for Girls and was subsequently occupied by Seton Hill College in 1918.
He died of liver cancer in 1923.