Sabatino Enrico 'Nello' Rosselli (Rome, 29 November 1900 – Bagnoles-de-l'Orne, 9 June 1937) was an Italian Socialist leader and historian.

Rosselli was born in Rome to a prominent Jewish family. His parents were Giuseppe Emanuele "Joe" Rosselli (1867 - 1911) and Amelia Pincherle (1870 - 1954), who was the paternal aunt to writer Alberto Moravia. Nello was the youngest of three sons, the others being Aldo Sabatino (1895 - 1916), died in World War I and Carlo Alberto (1899–1937).^[1] Nello was a member of the reformist Unitary Socialist Party of Filippo Turati, Giacomo Matteotti and Claudio Treves, which had split from the PSI. After the rise of Fascism, he fled to France with his brother, and became active there in anti-Fascist and socialist politics, helping to found the group Giustizia e Libertà and aiding the Republicans in the Spanish Civil War, as well as carrying out propaganda missions within Italy.

In June 1937, Nello went to visit his brother, Carlo, at the French resort town of Bagnoles-de-l'Orne, Orne. On 9 June, the two were killed by a group of cagoulards, militants of the Cagoule, a French fascist group, with archival documents implicating Mussolini's regime in authorizing the murder.^[2][3][4][5] The two brothers were buried in the Père Lachaise Cemetery in Paris, but in 1951 the family moved them to Italy into the Monumental Cemetery of Trespiano, a frazione of Florence.^[3]

His wife Maria Todesco, their four children Silvia, Paola, Aldo and Alberto, and his mother Amelia Pincherle Rosselli survived him.