| Abbr. | Logo | Ideology | Founded | Founder | Leader | Website | European Parliament Group |
| SDE |  | Social Democracy | 08.09.1990 | Marju Lauristin | Lauri Läänemets | http://sotsid.ee |  |
Elections
| Elections | | % | Votes | Seats | |
| 2023 | | 9,27 | 56.584 | 9 | 5th |
| 2019 | EU | 23,30 | 77,375 | 2 | 2nd |
| 2019 | | 9,83 | 55.168 | 10 | 5th |
| 2015 | | 15,17 | 87.257 | 15 | 3rd |
| 2014 | EU | 13,90 | 44.550 | 1 | 4th |
| 2011 | | 17,09 | 98.302 | 19 | 4th |
| 2009 | EU | 8,69 | 34.508 | 1 | 5th |
| 2007 | | 10,61 | 58.363 | 10 | 4th |
| 2004 | EU | 36,78 | 85.433 | 3 | 1st |
| 2003 | | 7,04 | 34.837 | 6 | 6th |
Party History
In 2003 Parliamentary Elections, the Party was called “Moderate Party”.
| Leaders |
| 1990 – 1995 | Marju Lauristin |
| 1995 – 1996 | Eiki Nestor |
| 1996 – 2001 | Andres Tarand |
| 2001 – 2002 | Toomas Hendrik Ilves |
| 2002 – 2009 | Ivari Padar |
| 2009 – 2010 | Jüri Pihl |
| 2010 – 2015 | Sven Mikser |
| 2015 – 2019 | Jevgeni Ossinovski |
| 2019 – 2022 | Indrek Saar |
| 2022 – | Lauri Läänemets |
