Singapore President Tony Tan Keng Yam paid his respects to Thailand's late King Bhumibol Adulyadej yesterday in the Grand Palace in Bangkok.
Dr Tan, who was accompanied by his wife Mary, as well as officials from Singapore's Foreign Affairs Ministry, laid a wreath by the late monarch's royal urn and signed the condolence book.
His visit came three days after Prime Minister Lee Hsien Loong travelled to Bangkok to do the same.
Since Mr Lee's visit, many regional leaders have travelled to the Thai capital to pay their respects.
They include Malaysian Prime Minister Najib Razak, Cambodian Prime Minister Hun Sen and China's Vice-President Li Yuanchao.
Indonesian President Joko Widodo will travel to Bangkok today to honour the late monarch.
King Bhumibol died on Oct 13 at the age of 88 in Bangkok's Siriraj Hospital after a long illness. The revered monarch, who reigned for 70 years, was a unifying figure in a country of 68 million now afflicted by a deep political divide.
Former privy council president Prem Tinsulanonda, 96, is currently standing in as Regent after Crown Prince Maha Vajiralongkorn asked for time to mourn with the people before his ascension to the throne.
In a Facebook post yesterday, Dr Tan said the late monarch was "well-loved by the Thai people because of his compassion and concern for his people".
"King Bhumibol was also a close friend of many countries, including Singapore. Under his long reign, the bilateral relations between Singapore and Thailand strengthened significantly," he wrote.
"King Bhumibol will be dearly missed by all. His legacy will remain an inspiration for generations to come."