[2] On 21 July 2017, the Philippine Sports Commission (PSC) announced its decision to withdraw support for the country's hosting of the 2019 SEA Games.

[3][4] Additionally, it was later reported that the Philippine Olympic Committee's (POC) insistence on handling all aspects of the hosting—including finances, security, and the organization of the Games, similar to how it managed the 2005 SEA Games—contributed to the PSC's decision to withdraw its support.

[5] On 10 August 2017, Charouck Arirachakaran, the Vice President and Secretary General of the National Olympic Committee of Thailand (NOCT), stated that Thai Prime Minister Prayut Chan-o-cha had agreed to a replacement plan for the 2019 SEA Games following the Philippines' withdrawal.

This decision came after Cojuangco wrote to Philippine President Rodrigo Duterte, appealing for reconsideration of the country's earlier withdrawal.

[7] In December 2021, Thailand was nominated as the host country for the 2025 SEA Games during the SEAGF Council and Executive Board Meetings held in Hanoi, Vietnam.

On October 11, 2022, Chaipak Siriwat, the Vice President of the National Olympic Committee of Thailand (NOCT), revealed the framework for the bidding process for the 2025 SEA Games.

He emphasized that the host cities or provinces should aim to organize the Games at a budget-friendly cost and that there would be no requirement to build new venues.

[13] In October 2022, Prachum Boontiem, the Vice Governor of the Sports Authority of Thailand (SAT), nominated eight bidding parties from twelve cities or provinces interested in hosting the 2025 SEA Games.

The city Bangkok as well as the provinces of Chiang Mai, Nakhon Ratchasima, and Songkhla submitted sole bids, while Bangkok, Chonburi, Songkhla, Krabi, Phuket, Trat, Amnat Charoen, Sisaket, Ubon Ratchathani, and Yasothon were proposed as potential bidding provinces.

[34] The event also featured renowned athletes, including Vareeraya Sukasem, an Olympic skateboarder, and Saysunee Jana, a five-time Paralympic gold medalist in wheelchair fencing.

Additionally, several celebrities joined the occasion, such as Matthew Deane, Khemanit Jamikorn, James Fagerlund, and Nakorn Silachai.

The games aim to achieve net-zero emissions by promoting eco-friendly transportation, utilizing sustainable products, and selecting venues that prioritize environmental protection.

[36][37] This environmentally friendly vision will also be implemented in the 2025 FIVB Women's Volleyball World Championship, scheduled for August earlier in the year.

[55] Inspired from the opening ceremony of the 2024 Summer Olympics and Paralympics in Paris, France, Sorawong Thienthong, Minister of Tourism and Sports (MOTS) revealed plans to hold part of the ceremony outside traditional stadium settings, utilizing venues designed to accommodate large public gatherings.

[56] Gongsak further disclosed that Sanam Luang, set against the backdrop of the Grand Palace, will serve as the main venue for the opening ceremony, with Chonburi and Songkhla still playing significant roles in the event.

[58] In the past, the public square also usually served as a venue for kite flying and hosting the national club sepak takraw championships.

[61][62][63][64][65][66][67] This practice highlights the vulnerability of the Southeast Asian Games Federation (SEAGF) and its Charter and Rules, which grant excessive power to the host nations.

[70] Although the Charter and Rules have been amended multiple times since then, host countries were still allowed to allocate their optional sports programs without oversight from the SEAGF.

Section 34 of the amended SEAGF Charter and Rules stipulates that starting with the 2025 edition, the SEA Games program will include a minimum of 41 sports.

All of these sports are included in the Thailand National Games, and the host cities and provinces are equipped to provide the necessary venues and facilities to accommodate these events.

[77][78] Marathon swimming, Muay Thai (muaythai), netball, and winter sports—including figure skating, ice hockey, and short track speed skating—will also return, having last been featured in 2019.

[109][110] Many traditional disciplines within these sports were included, such as the compound bow and recurve bow in archery; canoe sprint in canoeing; dressage, eventing, and show jumping in equestrian; épée, foil, and sabre in fencing; field hockey and indoor hockey in hockey; combat and kata in judo; ne-waza, fighting, and duo in ju-jitsu; kumite and kata in karate; ring and tatami in kickboxing; triathle and biathle in modern pentathlon; combat and waikru in muaythai; regu, quadrants, and hoop in sepak takraw; pistol, rifle, and shotgun in shooting; kyorugi and poomsae in taekwondo; duathlon and aquathlon in triathlon; freestyle wrestling and Greco-Roman wrestling in wrestling; and sanda as well as taolu in wushu.

[115][116] In December 2024, the organizing committee introduced an additional sixteen medal events across various sports, including athletics, dragon boat, track cycling, rhythmic gymnastics, judo, sailing, esports, pencak silat, and woodball.

This increased the total to 585 events, surpassing the previous record of 580 set at the 2023 SEA Games in Phnom Penh, Cambodia.

Since its debut in 2003, Timor-Leste will participate for the first time as a full ASEAN member state, with its official access to the association expected in 2025.

[123][124] The official awarding ceremony took place at the Chaloem Phrakiat Building at the Hua Mak Sports Complex in Bangkok on 23 November 2023.

The initial emblem, created by Ruengwit Phutharaporn, was inspired by the pla kat, or Siamese fighting fish, Thailand's national aquatic animal.

The initial mascot, named Mawin, was designed by Tawich Jitthiang and depicted a Waree Kunchorn, a mythical creature from the Himavanta.