There are no direct flights from Australia and new Zealand to Sri Lanka, only with a transfer through Singapore, Kuala Lumpur and Bangkok. The most regular flights are operated by Qantas (qantas.com) and their budget subsidiary Jetstar (jetstar.com), which make flights to Singapore (from Sydney, Melbourne, Perth and Brisbane) and Bangkok (from Sydney and Melbourne), where you can directly fly to Colombo. Tariffs from Sydney to Colombo usually start from 1000 AUS$, and from Auckland – about 1500 NZ$.
Regular direct flights connect Sri Lanka and other countries of South and South-East Asia: India, including Delhi, Mumbai (Bombay), Chennai (Madras), Bangalore, Thiruvananthapuram (Trivandrum), Kochi and Tiruchirappali; Maldives (male); Thailand (Bangkok); Malaysia (Kuala Lumpur); Singapore; Japan (Tokyo); China (Hong Kong, Beijing and Shanghai).
Check the current prices of flights to Sri Lanka