Winners of SLNCO 2025
| Gold | Deveni Guruge Himaru Abeygunarathne | Trinity College, Kandy |
| Silver | Januki Vihasna Cooray | Badulla Central College, Badulla |
| Bronze | Rithmini Dinhara Weerakkody | Sirimavo Bandaranaike Vidyalaya, Colombo 07 |
| Bronze | Srikaran Menan | St. John’s College, Jaffna |
| Bronze | A.K. Methmaka Chethila Jayasena | Royal College, Colombo 07 |
| Honorable mention | K.M. Suparna Samadhie Somaratne | Mahamaya Girls’ College, Kandy |
| Honorable mention | Pumuditha Thisath Edirisooriya | Royal College, Colombo 07 |
| Honorable mention | Kalu Arachchige Don Idusara Pulasthi Gajaba Wijerathna | Ananda College, Colombo 10 |
| Honorable mention | Dehan Nisaja Damseth Karunathilake | Dharmaraja College, Kandy |
| Honorable mention | Sineth Chandil Fernando | St. Benedict’s College, Colombo 13 |
| Honorable mention | Dinath Sathnidu Ranasinghe | Ananda College, Colombo 10 |
| Honorable mention | Minula Pehesara | Vidyaloka College, Galle |
| Honorable mention | Senitha Minadith Senaratne | Ananda College, Colombo 10 |
Winners of SLNCO 2024
| Gold | Robolge Pahanma Upani Lenora | Sanghamiththa Balika Vidyalaya, Galle |
| Silver | Sreemaathuri Sinthanaichselvan | Ramanathan Hindu Ladies’ College, Colombo |
| Bronze | U. A. Githma Himakara | Richmond College, Galle |
| Bronze | Sithupa Danithu Nethmina Palihawadana | Royal College, Colombo |
| Bronze | Vajra Neth Wijesooriya | Ananda College, Colombo |
| Bronze | Kenul Luthmin Perera | Lyeceum International School, Wattala |
| Honorable mention | Akila Chamodya Bandara | Kingswood College, Kandy |
| Honorable mention | Januki Vihasna Cooray | Badulla Central College, Badulla |
| Honorable mention | Srikaran Menan | St.John’s College, Jaffna |
| Honorable mention | Nesith Lakvindu Hettiarachchi | Ananda College, Colombo |
Winners of SLNCO 2023
| Gold | Senumi Nudara Weerackody | Visakha Vidyalaya, Colombo |
| Silver | Kuragodage Thisarindu Adeepa Lakshan | Richmond College, Galle |
| Silver | Isitha Dinujaya Arachchi | Ananda College, Colombo |
| Bronze | Thuvarahan Chandrakumar | S. Thomas’ College, Mt. Lavinia |
| Bronze | Robolge Pahanma Upani Lenora | Sanghamiththa Balika Vidyalaya, Galle |
| Bronze | Ashen Umendra Perera | Dharmaraja College, Kandy |
| Honorable mention | Lasan Sanjula Perera | Ananda College, Colombo |
| Honorable mention | Yehan Sandes Jayasuriya | Royal College, Colombo |
| Honorable mention | Sithupa Danithu Nethmina Palihawadana | Royal College, Colombo |
| Honorable mention | Don Nipun Dinuka Adikari | De Mazenod College, Kandana |
Winners of COSL 2022
| Gold | Nelushi Vithanachchi | Visakha Vidyalaya, Colombo 05 |
| Silver | Nilakna Disiwari Warushavithana | Visakha Vidyalaya, Colombo 05 |
| Bronze | Benuljith Karunarathne | Royal College Colombo 07 |
| Bronze | Kavinda Chathuranga | Nalanda College, Colombo 10 |
| Bronze | Vasanthamohan Sasangan | St. Michael’s College, Batticaloa |
| Honorable mention | Thiyumi Amaya Samarakoon | Visakha Vidyalaya, Colombo 05 |
| Honorable mention | Shasmitha Akashwara Liyanage | Mahinda College, Galle |
Winners of COSL 2021
| Gold | Nadun Naveendra Rajapaksha | Dharmaraja College, Kandy |
| Silver | Manujaya Praveen Wijesinghe | Royal College, Colombo |
| Silver | Kelambi Arachchige Achira Hansindu | Mahinda College, Galle |
| Bronze | Dinithi Shalika Madhubhashini | Southlands College, Galle |
| Honorable Mention | Makarathan Karunairasan | Thalawakelle Tamil Maha Vidyalaya |
| Honorable Mention | Hewa Bahithage Ruchini Niwarthana | Pushpadana Girls College, Kandy |
Winners of COSL 2020
| Gold | Sajini Nadara Boyagoda | Girls’ High School, Kandy |
| Silver | Arulanantham Abbinanthan | Hindu College, Jaffna |
| Silver | Uvindu Praveen Sumanasekara | Badulla Central College |
| Bronze | Jeyanandarasa Kirushikan | Hindu College Jaffna |
| Honorable Mention | Chanupa Devnith Wijesinghe | Dharmaraja College |
| Honorable Mention | M.B.Shakindi Vihangana | Sujatha Vidyalaya, Mathara |
Winners of COSL 2019
| Gold | R. M. Sugath Ravindu Sanwara | Ananda College, Col 10 |
| Silver | Thishanka Alahakoon | Dharmaraja College, Kandy |
| Bronze | R. M. P. Akila Prabodha Rajapaksha | Bandaranayake College, Gampaha |
| Merit award | W. M. Buddhi Saumya Kumara Wijenayake | St. Sylvester’s College, Kandy |
| Merit award | R. M. Nethmini Nirasha Rathnayake | St. Joseph’s Balika M.V, Kegalle |
| Merit award | P. B. K. Sanjana Gimhani Kapukotuwa | Maliyadewa Balika Vidyalaya, Kurunegala |
| Merit award | Anisha Jude Joachimson | Chundilkuli Girls’ College, Jaffna |
| Merit award | Sachintha Tashen Paranga Narangoda | Richmond College, Galle |
| Merit award | Sivathasan Tharsikan | Jaffna Hindu college |
| Merit award | R.P. Gnalitha Mithun Diumantha Samaranayake | Maliyadewa College |
| Merit award | Jeyanandarasa Kirushikan | Jaffna Hindu college |
Winners of COSL 2018
| Gold | Pavindu Udeesha Jayasekera | Richmond College, Galle |
| Silver | Anuki Chamathka Pasqual | Visaka Vidyalaya, Colombo |
| Bronze | Sanjana Gimhani Kapukotuwa | Maliyadewa Girls School |
| Bronze | Sugath Ravindu Sanwara | Ananda College, Colombo 10 |
| Bronze | Thinupa Anjana Wijetunga | Richmond College, Galle |
| Merit award | Charuka Nishala Kulathunga Bandara | R/E Ehaliyagoda National School |
| Merit award | Mahanaida Badalgei Shakindi Vihangana | Sujatha Vidyalaya |
| Merit award | Uvindu Praveen Sumanasekara | Badulla Madya Maha Vidyalaya |
| Merit award | Sachintha Tashen Paranga Narangoda | Richmond College |
| Merit award | Sivathasan Tharsikan | Jaffna Hindu College |
| Merit award | Arulanantham Abbinanthan | Jaffna Hindu College |