Émile Joseph Marie Piétri (25 February 1820 – 4 January 1902), known as Joachim Pietri, was a French lawyer and public servant who was prefect of several departments, a repressive police chief of Paris in the last years of the Second French Empire and Bonapartist Senator of Corsica from 1879 to 1885.

[1] He also suppressed the demonstration in honour of Charles Augustin Sainte-Beuve, who had defended Ernest Renan in the senate.

[4][c] Piétri did not moderate the violence of his agents, and in December 1867 sent a circular to the police commissioners "to guard against any hesitation or failure."

After discovery of the plot that was judged at Blois in 1870 he encouraged the demonstrations on the boulevards of Paris in favour of war with Prussia.

Although he did not qualify on age or years of service, a decree in April 1873 fixed his pension arrears at 6,000 francs.

Léon Renault, the prefect of police, reported in January 1875 that Piétri was one of the most active members of the Bonapartist committee.

[4] On 22 June 1879 Piétri was elected Senator of Corsica on an imperialist platform by 256 votes against 227 for his opponent, Tomasi.

He voted against the application of laws to religious congregations, against changes to the judicial oath, against reform of the magistrature and against restoration of divorce.