Myanmar will be the third team in Group B and will be joined by a qualifier following Wednesday's draw.
The event, held every two years, will be co-hosted by Vietnam and Indonesia in December following a four-team qualifying event in Laos in October.
In Group A, co-hosts Indonesia, who played in three straight finals from 2000 but have yet to win the tournament, will meet three-times champions Thailand, coached by former England captain Bryan Robson, and Malaysia, who are on a high after winning the SEA Games football title last December.
Two spots were left open in the draw for the first and second-placed teams from qualifying at the National Sports Complex in Vientiane involving hosts Laos, Cambodia, Philippines and East Timor from October 22-26.
Vietnam lifted the trophy for the first time in 2008 with victory over Thailand in the two-legged final and coach Henrique Calisto is bullish about his side's chances once again.
"We aim to defend our title. I believe we will win," he told local media.
Vietnam will prepare by playing North Korea and the Under-23 teams from Australia and Kuwait in a round-robin tournament from September 20-24 to mark the 1,000th anniversary of the founding of the nation's capital, Hanoi.
Singapore coach Radojko Avramovic was happy with his Lions' chances too.
"The group we are in is slightly easier than the other group where there will be three title contenders in Thailand, Malaysia and Indonesia," he told reporters.
"Overall, I am happy with the draw. Our target in this tournament is to reach the final."
