Mr Masagos Zulkifli was sworn in as a minister by President Tony Tan Keng Yam at a ceremony in the Istana yesterday.
He is now a Minister in the Prime Minister's Office, and Second Minister for Foreign Affairs as well as Home Affairs.
Previously, he was Senior Minister of State at the two ministries, positions he held since 2012.
Given the extensive issues covered by the two ministries, Mr Masagos will be "a great help", said Prime Minister Lee Hsien Loong, who witnessed the swearing-in.
In a Facebook post yesterday, he also praised Mr Masagos' "sincerity, ability and hard work".
Yesterday, congratulatory messages continued to pour in for Mr Masagos, who turns 52 next week.
Foreign Minister K. Shanmugam said the new appointment will strengthen his ministry.
He also noted Mr Masagos' work with his ministry to bolster ties with Malaysia and Indonesia.
"Masagos has promoted Singapore at every opportunity, and has been very good for us," said Mr Shanmugam.
Senior Minister of State for Finance and Transport Josephine Teo - who entered politics at the same time as Mr Masagos in 2006 - said it was a "most well-deserved" promotion.
She praised him for his "strong powers of observation and deep analytical skills".
He is also a "great family man" who would chip in to do household chores, she said.
Emeritus Senior Minister Goh Chok Tong said Mr Masagos is a "good addition to the Cabinet team".
"He is humble, sincere and dedicated," he wrote on Facebook. The latest Cabinet changes add "depth and breadth to those who will lead Singapore forward", he said.
"Stretching the younger ministers will strengthen their resilience," he added.
Besides Mr Masagos' promotion, the latest - and fifth - Cabinet changes since the May 2011 General Election saw a new labour chief and new portfolios for three other ministers.
Mr Chan Chun Sing, 45, will be labour chief from May 4, taking over from Mr Lim Swee Say, 60.
Manpower Minister Tan Chuan-Jin, 46, took over Mr Chan's portfolio yesterday.
On May 4, he will hand his Manpower portfolio to Mr Lim.
Meanwhile, Transport Minister Lui Tuck Yew, 53, assumed a concurrent appointment as Second Defence Minister yesterday.
This article was first published on April 10, 2015.
Get a copy of The Straits Times or go to straitstimes.com for more stories.