Historical Milestones
| September 1985 | Completion of original school building |
| January – March 1986 | Building housed Yishun Secondary School, Yishun Town Secondary School and Yishun Junior College |
| 29 March 1986 | YSS and YTSS shifted to YTSS |
| 1 December 1986 | Mr Leong Kah Chong appointed as Principal |
| 17 December 1986 | Shift back to existing building |
| 19 August 1986 | Official opening by Dr Koh Lip Lin, Nee Soon MP |
| December 1995 | Mr Soh Guan Ba appointed as second Principal |
| Second Semester 1999 | Single session after completion of the new extension block started |
| December 2000 | Mr Ow Chiong Hoo appointed as third Principal |
| June 2002 | Commencement of PRIME |
| December 2002 | Mr Goh Choon Leng appointed as fourth Principal |
| June – October 2006 | Twentieth Anniversary Celebrations Publication of My Yishun: Recounting, Reflecting, Reminiscing |
| December 2008 | Ms Ng Ngoing Keng appointed as fifth Principal |
| July – October 2011 | Official Opening of YSS Heritage Walk |
| April 2011 | YSS’s inaugural Arts Extravaganza |
| December 2014 | Mdm Ng Shok Yan appointed as sixth Principal |
| December 2018 | Ms Regina Lee appointed as seventh Principal |