Bulgarian Socialist Party

Founded as the legal successor to the Bulgarian Communist Party, the BSP describes itself as a democratic socialist party, espousing socialist policies and values, while supporting a social market economy. It has also been described as a populist and social-democratic party. The party's policies have oscillated during its existence from a customary understanding of socialism during the Videnov era, to a more social-liberal worldview under Stanishev, to a socially conservative strain of socialism under Ninova.

Like most Party of European Socialists (PES) member parties, the BSP has a pro-European stance, although it has taken some Eurosceptic positions and called for an end to sanctions against Russia. Some news outlets, such as Novinite, The Wall Street Journal, and The Washington Post, have described its orientation as soft Russophilia.

In recent times under the leadership of Korneliya Ninova and unlike the majority of PES parties, the BSP has been described as more conservative on social issues, and like European Union politics it is more divided, with some leaders, such as Ninova, opposing same-sex marriage in Bulgaria. Many party leaders opposed the Istanbul Convention because they were against educating children about sexuality if it also meant same-sex relationships, and after a long debate decided to vote against it, despite internal division about it. Former BSP leader and then-PES head Sergey Stanishev strongly supported the Istanbul Convention. Under Ninova's leadership, BSP additionally shifted to a more nationalist position.

Chairperson: Aleksandar Lilov (3 April 1990–12 December 1991), Zhan Videnov (12 December 1991 – 21 December 1996), Georgi Parvanov (21 December 1996 – 5 December 2001), Sergey Stanishev (5 December 2001 – 27 July 2014), Mihail Mikov (27 July 2014 – 8 May 2016), Korneliya Ninova (8 May 2016 – 15 June 2024), Atanas Zafirov (15 June 2024 – 7 February 2026), Krum Zarkov (since 7 February 2026).