Leonard Marconi (Warsaw, 6 October 1835 – 1 April 1899, Lemberg) was a Polish architect and sculptor active in Warsaw and in Austrian Galicia, notably Lemberg (Lwów, now Lviv, Ukraine).

Leonard Marconi was born on 6 October 1835 in Warsaw to a well-known artistic family of Italian origin.

He graduated from the Academy of Fine Arts in Warsaw, then the Accademia di San Luca in Rome.

Fairly successful as a sculptor, in 1873 he was invited to Lwów (then in Austro-Hungarian Galicia) to become a professor at the Technical Academy (Polish: Akademia Techniczna), predecessor of the Lviv Polytechnic.

He died in Lviv on 1 April 1899 and is interred at Lychakiv Cemetery.