The telco, which is also the parent company of Australia's second biggest operator, Optus, said in a statement that it would now deploy the new speed across the island as more spectrum was allocated for the LTE network.
Smartphones that can support 1.5Gbps are expected to come on the market next year.
“We are constantly investing in innovative technologies to boost network speeds, enhance coverage and expand capacity to give our customers the best network experience,” said Yuen Kuan Moon, chief executive, Consumer Singapore, and group chief digital officer at Singtel.
Singtel said the speed was achieved in collaboration with Ericsson with a first-of-its-kind carrier aggregation of five carriers, which boosts network bandwidth.
A combination of two 1800 MHz frequencies, together with 2100 MHz, 2600 MHz and TDD 2500 MHz spectrum bands and technologies such as FDD & TDD, 256QAM and 4X4 MIMO, was used to achieve 1.5Gbps.
"When introduced in the live network, such capability improves user experience and enhances network capacity. For instance, customers can download a two-hour 4K video in eight minutes," the company said.
Singtel and Ericsson will launch a pilot 5G network in Singapore in the fourth quarter of 2018.
“Ericsson has been a leader in pioneering technologies,” said Martin Wiktorin, head of Ericsson Singapore, Brunei and the Philippines.
“By leveraging five-carrier aggregation across both FDD & TDD, we continue to lead the way to meet customers speed and capacity demands. We are proud to be working on new capabilities and advancements on LTE."