Singapore sovereign wealth fund GIC Pte Ltd is also considering investing in the IPO, said one of the people.
Temasek, GIC and Ant declined to comment.
Ant, backed by Alibaba Group Holding, plans to list simultaneously in Hong Kong and on Shanghai's Nasdaq-style STAR Market and raise as much as $30 billion, Reuters has reported.
That would make it the world's biggest IPO since Saudi Aramco raised $29.4 billion last December, which surpassed the record set by Alibaba in 2014.
Temasek and GIC are the first major Asian investors to be linked to Ant's IPO.
The potential investments by two of the world's biggest state investors underscore that Ant's mammoth IPO is gaining traction. Temasek and GIC also participated in Ant's $14 billion funding round in 2018.
The sources declined to be identified as news of Temasek and GIC's potential investment has not been reported.
Temasek is mulling investing in both the onshore and offshore legs of the dual listing, which could come as soon as October, said the second source.
The state investor is awaiting more details of Ant's IPO before finalising its investment proposal, said the first person.
Temasek's portfolio exposure to China, as measured by underlying assets, increased to a record 29% in the year ending March, from 26% a year earlier, while exposure to Singapore fell to 24% from 26%.
Ant, China's dominant mobile payments firm, plans to raise more funds on STAR than in Hong Kong, in a major endorsement of the year-old mainland exchange, Reuters has reported. It will seek listing approval from the Shanghai stock exchange on Sep. 18.
On Thursday, Reuters reported that Saudi Arabia's sovereign fund PIF, is weighing a potential investment in Ant's IPO.
By Anshuman Daga and Julie Zhu