Weerawansa was born to W. Cosmas Damian (Teachers' Training College Lecturer) and Mercy Edna (English-trained teacher) on 17 June 1966 at Negombo, Sri Lanka. A Navodaya scholar, he was educated at the Royal College, Colombo - Senior College Prefect 1984/85 and Hostel Prefects' Advisor 1984/86. He then pursued further studies at the Thomson Foundation in the UK, and graduated from the International Olympic Academy (IOA), affiliated to the University of Athens. In 1994, he was selected by the Ministry of Foreign Affairs in Japan to represent Sri Lanka at the South Asian Youth Exchange program. Only Sri Lankan media personality to be trained in the world-renowned IOA in Athena, Greece. Holds a diploma in sports leadership conducted by the International Olympic Committee (IOC).
He is a honorary member of the International Taekwon-Do Federation he has been Sri Lanka’s prolific Sports Editor / sports journalist for over three and a half decades and is also the IAAF athletic correspondent for Sri Lanka. He is the most experienced and widely travelled sports writer in Sri Lanka who has covered a record seven editions of the Olympic Games (1992, 2000, 2004, 2008, 2012, 2016 and 2020), eight IAAF World Athletic Championships (2001, 2003, 2005, 2007, 2009, 2011, 2013 and 2015) and six Asian Games (1994, 1998, 2002, 2006, 2010 and 2014).
Weerawansa has covered many milestone events in Sri Lanka sport, including Susanthika Jayasinghe winning the 2000 Sydney Olympic Games silver medal and 2007 World Championship bronze medal as well as Damayanthi Darsha and Sugath Tillakaratne winning gold medals for Sri Lanka (3) after 25 years at 1998 Bangkok Asian Games. He had also served as a radio and television commentator at several international events, including Olympic Games, Asian Games, South Asian Games and Test/ ODI international cricket matches and represented Sri Lanka at the Asian Sports Press Union Congress in Seoul in 1990 and 1992 and South Asian Sports Association in Dhaka, 1993 - was elected Chairman of its Cricket Commission.