A year after the Philippines regained full sovereignty from the United States on July 4, 1946, the Municipality of Buayan became a 4th class regular municipality by virtue of the Executive Order Number 82, dated August 18, 1947 by President Manuel Roxas, absorbing the Municipal District of Glan, whose low income bracket at the time disqualified it for the honour.
Dadiangas was the seat of government for the Municipality of Buayan electing Irineo Santiago as its first Municipal Mayor on a local election that was held on November 11, 1947.
Mayor Santiago was formally inducted on January 1, 1948.

Six years later, in June 1954, the Municipality of Buayan was renamed General Santos as a tribute to the leading pioneer via Act No.
1107 authored by Congressman Luminog Mangelen of Cotabato Province.

From 1963 to 1967, the municipality's economy experienced a boom under Mayor Lucio A. Velayo, as several large agri-based and multinational firms such as Dole Philippines, General Milling Corporation and UDAGRI expanded into the area.
Although it was then qualified to become a fourth class city from being a municipality, the residents rejected a move by Congressman Salipada Pendatun to convert the Municipality of Buayan into a city and to rename it ’’Rajah Buayan’’.

On July 8, 1968, the Municipality of General Santos was converted into a city upon the approval of Republic Act No.
5412, authored by Congressman James L. Chiongbian.
It was inaugurated on September 5 of that year, with Antonio C. Acharon became the new city's first mayor.
On September 5, 1988, a decade after its inauguration as a chartered city, GenSan was declared a highly urbanized city of South Cotabato.
A year after the Philippines regained full sovereignty from the United States on July 4, 1946, the Municipality of Buayan became a 4th class regular municipality by virtue of the Executive Order Number 82, dated August 18, 1947 by President Manuel Roxas, absorbing the Municipal District of Glan, whose low income bracket at the time disqualified it for the honour. Dadiangas was the seat of government for the Municipality of Buayan electing Irineo Santiago as its first Municipal Mayor on a local election that was held on November 11, 1947. Mayor Santiago was formally inducted on January 1, 1948.
Six years later, in June 1954, the Municipality of Buayan was renamed General Santos as a tribute to the leading pioneer via Act No. 1107 authored by Congressman Luminog Mangelen of Cotabato Province.
From 1963 to 1967, the municipality's economy experienced a boom under Mayor Lucio A. Velayo, as several large agri-based and multinational firms such as Dole Philippines, General Milling Corporation and UDAGRI expanded into the area. Although it was then qualified to become a fourth class city from being a municipality, the residents rejected a move by Congressman Salipada Pendatun to convert the Municipality of Buayan into a city and to rename it ’’Rajah Buayan’’.
On July 8, 1968, the Municipality of General Santos was converted into a city upon the approval of Republic Act No. 5412, authored by Congressman James L. Chiongbian. It was inaugurated on September 5 of that year, with Antonio C. Acharon became the new city's first mayor. On September 5, 1988, a decade after its inauguration as a chartered city, GenSan was declared a highly urbanized city of South Cotabato.
General Santos