In 2014, Ho was blacklisted by the Chinese government and dropped by the luxury brand Lancôme for her participation in the Umbrella Movement in Hong Kong.

On 28 December 2021, Ho was arrested by the Hong Kong police under the joint charges of both production and distribution of seditious materials.

[4][10] This gave her the opportunity to meet Anita Mui, a renowned singer of Cantopop[4]—"queen of Hong Kong movies and…renowned in the… world of Cantonese pop music"[11]—of whom she had been a fan since childhood,[12][10] and who would become her mentor following her win.

In the intervening period between the contents win and her first album, Ho toured as a background vocalist with Mui,[13] and hosted various television programs produced by TVB.

Produced by Choy Yat Chi of Grasshopper (band), this EP, containing her first single "Thousands More of Me" (千千萬萬個我) and "Home of Glory" (光榮之家), defined with success Ho's style as the rock pop independent female she is up till recent years.

[3] Another single in the EP, "Rosemary" (露絲瑪莉), written by Wyman Wong, created considerable controversies at the time, as it touched on the topic of lesbianism.

[15] In 2002, Ho's two singles "Angel Blues" (天使藍) and "Goodbye... Rosemary" (再見...露絲瑪莉) won multiple music awards in Hong Kong, including CASH Golden Sail Music Awards (CASH金帆音樂獎) – "Best Vocal Performance by a Female Artist" for the song "Angel Blues".

In July, she released her new song "The Old Testament" (舊約) and announced that she would hold her "SUPERGOO" themed concerts from 9–12 October that year.

Following the concerts, Ho took on a role in the new stage comedy "Man and Woman, War and Peace" (男人與女人之戰爭與和平) directed by Edward Lam.

[28][29] Her active participation in Hong Kong's large-scale social movement led her to be blacklisted and banned from performing in China.

So she came up with a crowdfunding alternative she called “Togetherly Exclusive.” She invited individuals and small and medium enterprises to pledge sponsorship for the event.

Eventually, sponsored by over 300 small enterprises and individuals, the four-day concert was successfully held and revisited 24 of the singer's greatest hits.

[34] At the end of 2018, she successfully organized a 6-day event called “On The Pulse Of” Festival in Hong Kong Science Park.

Ho, as a Canto-pop star turned activist, got worldwide media coverage due to her active participation in the movement.

During her short speech, she called on the council to remove China from the body and convene an urgent session to protect Hongkongers, sparking two interruptions by Chinese delegate Dai Demao.

[38] On 20 August, Ho participated in Singularity University's (SU) annual Global Summit and did a keynote speech about how Hong Kong people utilize technology in their social movements.

[39] On 29 December 2021, Ho and five other people linked to Stand News, including barrister Margaret Ng,[40] were arrested by Hong Kong Police on suspicion of breaching the colonial-era law covering conspiracy to print or distribute seditious materials.

[43] When asked about the origins of her "passion for freedom of expression," Ho replied to reporter Frédéric Lelièvre of La Presse that it was probably from her being an adolescent in Montreal at the time of the 1995 Quebec referendum.

[4] Ho proudly announced herself as "tongzhi" (Cantonese: tung4 zi3), a Chinese slang term for homosexuals, at age 35, at the fourth annual Hong Kong Pride Parade on 10 November 2012.

Days later, she watched in appalled amazement as the city's parliament struck down a motion to launch a public consultation on LGBT discrimination.

[48] In 2014, Ho made her stance clear when police fired tear gas in a futile attempt to disperse thousands of mostly-young pro-democracy protesters who had taken to the streets for the "Umbrella Movement".

[49] This action was taken in response to a boycott campaign launched by the Communist Party-controlled Global Times, which accused her of supporting Hong Kong and Tibet independence, and backlash from mainland Chinese internet users.

[4] Shortly after the Lancôme incident, Ho announced a crowd-sponsorship campaign named "Togetherly Exclusive Sponsorship" for her Hong Kong Coliseum concert "Dear Friend,”.

In May 2019, Ho was invited to participate in Oslo Freedom Forum, a global platform for human rights defenders to share their stories.

According to Ho, China has engaged in kidnappings, jailed activists, disqualified pro-democracy lawmakers, and restricts universal suffrage.

"[56] Her speech at the UNHRC was in reference to the China extradition bill protests and the ongoing freedom and democracy movement in Hong Kong.

[57] During an interview prior to the UN session, Ho called Beijing's abuses a global issue, and mentioned Tibet and Xinjiang as regions also suffering from human rights violations.

[54][55] On 20 August, Ho participated in Singularity University's (SU) annual Global Summit and did a keynote speech about how Hong Kong people utilize technology in their social movements.

She attended the following events: Antidote 2019, a festival organized by the Sydney Opera House; "Be Water: Hong Kong vs China", a seminar co-organized with Badiucao in Melbourne; and this year's second Oslo Freedom Forum, which will take place in Taiwan.

"[58] A 90-minute documentary film produced by Sue Williams, Denise Ho: Becoming the Song, released on 1 July 2020 in solidarity with the protest, marking the 23rd anniversary of Britain's handover of Hong Kong to China in 1997.