SMS Preussischer Adler was a paddle steamer originally built in the mid-1840s for use on a packet route between the Kingdom of Prussia and the Russian Empire in the Baltic Sea. She was requisitioned by the Prussian Navy during the First Schleswig War in 1848 and converted into an aviso, the first vessel of the type commissioned by Prussia. During the war, she took part in an inconclusive action with the Danish brig , the first naval battle of the Prussian fleet. After the war, she was disarmed and returned to her commercial role, operating uneventfully on the Stettin–St. Petersburg route until 1862, when the expansion of the Prussian Eastern Railway had rendered the maritime route superfluous. The ship was purchased by the Prussian Navy that year and rearmed, once again as an aviso.