Hermann Gossler (born 21 August 1802 in Hamburg, died 10 May 1877 in Hamburg) was a Hamburg lawyer, senator (1842–77) and First Mayor and President of the Senate of the Free and Hanseatic City of Hamburg (i.e. the city republic's head of state and head of government) in 1874. He was Second Mayor in 1870, 1871 and 1873. During much of his tenure as senator and his first term as Second Mayor, Hamburg was a fully sovereign country, while after 1871, the First Mayor as head of state of republican Hamburg was equal to the federal princes (Bundesfürsten) within the German Empire. As a senator, he also served as Lord of Police (Polizeiherr), the equivalent of a Minister of Police.
He belonged to the Hanseatic Berenberg-Gossler banking dynasty and was a son of the banker and senator Johann Heinrich Gossler (1775–1842), co-owner of Joh. Berenberg, Gossler & Co, and the grandson of Johann Hinrich Gossler. His brothers Johann Heinrich Gossler (1805-1879) and Wilhelm Gossler continued the firm. His nephew Johann von Berenberg-Gossler was conferred Baronial rank in 1910.
Hermann Gossler studied law at the University of Heidelberg, and worked as a lawyer in Hamburg from 1826 to 1837. He became Senate Secretary (roughly comparable to Parliamentary Under-Secretary of State) in 1837. From 1838 to 1842, he was Secretarius of the High Court. In 1842 he was elected Senator.
He was the father of Emilie (Emmy) Helene Gossler (1838–1910), married to banker Georg Heinrich Kaemmerer.
- Deutsches Geschlechterbuch Band 19, (Hamburgischer Band 2), Hamburg 1911, S.29