Onsen-Yesilyurt is one of the localities of Kahramanmaras Merkez; it had 1,438 registered voters at the 2011 parliamentary election.
AK Parti took 1,022 of the 1,332 valid votes cast in the neighborhood at that election (76.7%). That puts the neighborhood 3.5 points below the party's district average. At the 2010 referendum 85.3% of the neighborhood voted 'yes' — 4.2 points below the district average.
The tightest race came at the 2009 local election: AK Parti took 364 votes to MHP's 356 — a margin of just 8 votes. Turnout at the 2009 local election was 96.5%, 7.8 points above the district average.