1952–2000

On 10 November 1952, MCOT was established as Thai Television Company Limited. "Thorathat" is the Thai word for television, despite Thailand having no television services at the time. Television services under the name Thai Thorathat (Channel 4) started on 24 June 1955 in time for national day celebrations.

In 1977 TTV Radio and Thailand Color Television Channel 9 moved to the present Huai Khwang headquarters in Bangkok and merged to form the Mass Communication Organization of Thailand (MCOT). In 1970, with the launch of Chong Sam (Channel 3;Defunct in 2020), its newest station, while the original Thai Thorathat (Channel Four) network was renamed Chong Kao (Channel 9).

Witthayu Tor Tor Tor ("TTV Radio") later became Radio MCOT on 25 March 1977 and became the nation's first 24-hour radio station.

Color television began in 1970 on Channel 3 and 1974 on Channel 9. Channel 9 was renamed Modernine TV in 2002.

2001–present

In 2005, the Ministry of Finance announced their plan to digitize free-to-air television broadcasts nationwide. Trial broadcasts were undertaken, involving 1,000 households in the Bangkok Metropolitan Area.

MCOT has prepared at least three new channels exclusively for digital television, besides the two initial channels, Modernine TV and Channel 3. Though the trials had been long over, the digital channels are (said to be) still active in test form.

In addition, MCOT would introduce regional television channels for each province in Thailand. Each of these regions will have its own dedicated television channel with localised content compared to national television making it about 80 television channels for a digitised MCOT as part of the state broadcaster's three-year restructuring plan. MCOT was expected to launch its digital terrestrial television services nationally in 2012. MCOT launched digital terrestrial television in 2013, with full service in 2014.

In March 2011, MCOT announced that it is also possible that MCOT may be planning to switch to DVB-T2 in some occasion.

Terrestrial television current channels

Logo history

• Thai Thorathat's first logo depicts images of "Witchu Prapha Dhewi" (Thai: วิชชุประภาเทวี), female angels and thunderbolts, adorned with clouds and lightning within a circle, designed by the Fine Arts Department of the Ministry of Education.
• In 1977, the same time of change to MCOT organization, the logo evolved into a circle. The center is white circle; the upper part is four sections divided by the curve of spread spectrum signals; the bottom curve is yellow, and next three sections are in primary colors of light (red, green, and blue); the lower part is yellow with the Thai letters "อ.ส.ม.ท." which is the abbreviation of the organization.

• In 2003, the time of change to MCOT PLC, the logo became circular gray lines intersecting like latitude and longitude, a purple figure which hides number 9 in the right part, and a gray curve in the upper part. Under this logo are the English letters "MCOT" in orange with gray border (convergence with Modernine TV, MCOT Modern Radio, and Thai News Agency)

Commercial breaks

The logo is shown on commercial breaks and test transmissions.

Clocks

The clock in Thailand was not in colour until 1974. Originally the clock was based on the clock tower in Bangkok in black and white. In 1974 the clock was yellow on blue.

Test card

Until the introduction of 24-hour broadcasting in 2002, MCOT used the PM5544 test pattern during the off-air hours of TV9 and EBU Colorbars on Channel 3. Until 2002, MCOT used the Philips PM5534 (PM5544 with clock) during off-air hours.

On-air and off-air

Currently both stations broadcast 24 hours a day.