Ethem Sarisuluk was one of at least eight people killed in clashes in June 2013 after police violently cracked down on a peaceful protest to save a central Istanbul park from redevelopment.
"Ethem's murderer is the AKP police," protesters shouted in Ankara, referring to the ruling Justice and Development Party. "This is only the beginning. We will keep on fighting".
The Sarisuluk family laid flowers at the site where Ethem was killed.
Sunday's protests followed violent clashes between police and protesters in Istanbul and Ankara marking the first anniversary of what have become known as the Gezi Park protests.
Police clashed with protesters in Istanbul Saturday, firing tear gas and water cannon at people clustered on side streets, defying a government ban on demonstrations on the iconic Taksim Square -- the epicentre of last year's turmoil.
In Ankara, police also clashed with protesters hurling fireworks and responded with water cannon and tear gas. One year on, the political tensions stemming from the Gezi revolt continue to simmer despite a decisive ruling party victory in March 30 local elections that has bolstered Prime Minister Recep Tayyip Erdogan's ambitions to stand for president in August.