Gialdino Gialdini (10 November 1842 - 6 March 1919) was an Italian composer and orchestra conductor.
Gialdini was born in Pescia, Tuscany, and studied at Florence with Teodulo Mabellini. He won a prize offered by the Pergola Theatre of that city for the best opera, with Rosmunda, which met, however, with an unfavorable reception when produced in 1868. After two more operas he tired of composing operas and started conducting opera productions, to international acclaim. In 1889 he conducted Wagner's Lohengrin at Bologna. Later he returned to composing operas. In September 1904 he became the Artistic Director of the Conservatorio Giuseppe Verdi in the then Austrian city of Trieste but had to abandon the post when Italy entered the war against Austria in May 1915. He then returned to his native Pescia for retirement, and died there aged 76.