The company almost halved its final dividend to 5.45 Singapore cents a share, down from 10.7 cents announced last year.
Weakness in the January-March quarter was exacerbated due to continuing data price competition and soft consumer sentiment in Australia, along with lower equipment sales and margins, the company said.
Singtel's operating revenue for the year slipped 2% to S$16.54 billion as the onset of the coronavirus outbreak in February pressured operations further.
The company did not provide guidance for the financial year ending March 2021 due to heightened uncertainty stoked by the spread of Covid-19, the potentially fatal illness caused by coronavirus.
Singtel, which is effectively the largest shareholder in Bharti Airtel, had to make provisions in its full-year results in relation to the Indian telco making payouts for spectrum charges and licence fees.