Peter Andreyevich Arshinov, also P. Marin (Пётр Андре́евич Арши́нов/П. Ма́рин in Russian; 1886–1937), was a metal worker from Yekaterinoslav who in 1904, joined the Bolshevik Party and began to edit the paper Molot (hammer). In 1906, to escape the attention of the police, he fled to Ekaterinoslav. There he became an anarchist.
On the 7th March 1907 he shot dead the boss of the railway workshops of Alexandrovska. Arrested on 9 March 1907 he was condemned to death by hanging by a military tribunal. In the night of 22 April 1907, he escaped with other prisoners during an Easter Mass, taking refuge in France.
In 1909, Arshinov returned to Russia and was caught smuggling arms from Austria. He was sentenced to 20 years imprisonment in Moscow, where he met Nestor Makhno. Both men were liberated by the Revolution in 1917, and in 1919, Arshinov joined Makhno and became involved in cultural and educational work in the area controlled by the Revolutionary Insurrectionary Army of Ukraine. He was also the leader of "Nabat" (Confederation of the Anarchist Organizations of Ukraine), and edited the paper Golos Anarkhista. In 1921, Arshinov emigrated from the country, in which time he would participate in the group Dielo Truda with Nestor Makhno. He was one of the authors of The Organizational Platform of the General Union of Anarchists. During his time in Berlin he would edit anarkhicheskii vestnik. He joined the communist party after returning to the USSR in 1930, but Arshinov was an obvious target for the purges and subsequently disappeared, probably being executed sometime around 1937.