Mediacorp's Channel 5 previously aired a simulcast of CNA during the weekday breakfast hours until 1 May 2019, when it was replaced by an Okto block.

Under the initially-planned format, the channel was set to provide business news mirroring CNN and CNBC, with a tentative launch date of 1 January 1999.

[8] In a surprise move, one of its initial presenters, Christine Tan, left CNA ahead of its launch for CNBC Asia.

[12] Channel NewsAsia launched on 1 March 1999, opening with a speech by Minister of Information and the Arts George Yeo at Raffles Place.

[14] A few months after launch, in July 1999, jurisdiction of CNA was moved from TCS to the newly-created MediaCorp News, in line with the renaming of SIM to Media Corporation of Singapore and the creation of "strategic business units".

It started to be distributed in other Asian countries and Australia by satellite on 28 September 2000,[16] after a decision taken on 1 March,[17] with the hopes of promoting it as a pan-Asian network.

[22] By late September 2001, the channel had achieved international targets two years ahead of schedule, with 12 million households and 35,000 hotel rooms in 15 countries receiving the service, showing strong demand for news from an Asian perspective.

Its output in Singapore, including the website, have reached record figures for the time, with its coverage of the aftermath of the September 11 attacks being seen by 35% of the Singaporean population, with Asia Tonight becoming the second most-watched English programme on local TV.

[26] The following month it signed a contract with Indonesian news network Metro TV, enabling the channel to have access to footage and programmes from CNA, with potential co-operation agreements between the two on the cards.

[35] Broadcasts in Thailand started in October 2004, after an agreement with the Thai Cable Television Association, which at the time comprised 170 member operators.

[20] CNA received praise from the Programme Advisory Committee (Pace) on 2 September 2009 for, among other things, its coverage of the 2008 United States presidential election and the political situation in Malaysia and Thailand.

[43] On 21 January 2013, CNA underwent a major relaunch, introducing a new studio at the Marina Bay Financial Centre, a new Mumbai bureau, an expansion in programming, and the new slogan "Understand Asia".

[46] Other bureaus the channel had opened at the time were Beijing, Hong Kong, Jakarta, Seoul and Tokyo; unofficial offices were also maintained in other cities such as Mumbai, New Delhi and Washington D.C.[citation needed] In September 2014, the channel announced plans to expand its studio in Kuala Lumpur, Malaysia, into a fully functional satellite office with high-definition capabilities.

In March 2019, marking the network's 20th anniversary, Mediacorp announced that Channel NewsAsia would officially rebrand as "CNA" full-time, citing a need to abandon a "TV-centric" identity to emphasise its multi-platform operations.

[50][51] In March 2024, the channel marked its 25th anniversary; CNA announced plans to further expand its presence in the United States, Canada, and the United Kingdom, launch a website in the Indonesian language (which will leverage AI-based translation software developed in partnership with the Agency for Science, Technology and Research), and bringing back the program East Asia Tonight beginning in April.

The international feed opts out of these programs, but also carries a simulcast of Channel 5's coverage of the Singapore National Day Parade annually on 9 August.