Bart Hubert Wilfried Marcel Staes (Dutch pronunciation: [bɑrt ˈstaːs]; born 7 August 1958), is a Belgian politician who served as a Member of the European Parliament for Flanders from 1999 until 2019.

Following the formation of the electoral alliance (cartel) between Spirit and the Socialistische Partij Anders (sp.a) in 2002, Staes moved to join Agalev (as it was then known; today, Groen).

He has been a Member of the European Parliament continuously since 1999, at first for the Volksunie, later Spirit and now Groen.

Staes was first elected into the European Parliament in 1999 and was reelected, as only member from his party, in 2004 and 2009.

During his time in parliament, he was part of The Greens–European Free Alliance transnational political group together with MEPs for the GreenLeft.