Olsen began his career with the Mangere East Hawks. In 1980, Olsen joined the Balmain Tigers. Olsen played 77 games for Balmain over 5 seasons (19 tries, 83 goals). In 1985, Olsen joined the Eastern Suburbs Roosters. Olsen played 8 games for Eastern Suburbs (21 goals). In 1986, Olsen joined the North Sydney Bears. Olsen played 18 games for North Sydney over two seasons. In 1990, Olsen captained the Ryde-Eastwood Hawks to victory in the Metropolitan Cup.
Olsen played for Auckland. Olsen played 28 games for New Zealand from 1977-86 (6 tries, 44 goals). Olsen captained Samoa in 1988.
In 1978, Olsen won the Rothville Trophy. In 2007, Olsen was inducted as a New Zealand Legend of League.
Olsen passed away on 10 February 2022.