More than 2500 people have expressed interest in coming on social media but regional manager Nina Field is expecting around 500 from 5.30pm.

Light the Night will start be near the base of the Flagstaff Hill lighthouse and the 2015 ambassador is Natasha Jauncey.

Mr Jauncey is in remission after her own battle with Hodgkin's lymphoma

She is joined by recent ambassadors David Campbell and Margaret Biggs who have both lost spouses to blood cancer.

More than 60,000 Australians live with blood cancer and 34 are diagnosed with leukaemia, lymphoma or myeloma daily.

Those carrying gold lanterns are remembering someone, those with white are going through their own journey and blue lanterns are to show you care. 

Light the Night is in its eighth year to raise funds for research and support.

Further information at www.lightthenight.org.au.