This is the highest result of Vietnam in this contest, where Ha overcame 64 contestants to take the top position on March 3.
The first runner-up went to Ifunanya Basilia Ikochukwu of Nigeria, while the second runner-up was Yashna Beeharry of Mauritius.
The third and fourth-placed spots were given to Ratana Sokhavatey of Cambodia and Genesis Guerrero of Ecuador.
Ha, 1.70m tall with measurements of 85-56-90cm, won the Best Eco Dress, a design inspired by Vietnamese traditional water puppetry, in the semi-finals to get a bye into the top 11.
In the Grand Finale, contestants participated in national costume and evening gown performances. Judgers picked up the top 21, top 11 and then top five.
The 19-year-old made a strong impression with her strikingly beautiful face, confidence and outstanding beauty in the national costume, and her gorgeous gown designed by Brian Vo, to go through to the top five.
In the interview round, she persuaded judges with her answers about the changes to society and the environment in the wake of the COVID-19 pandemic.
The beauty queen said that people's mental health problems must be well-taken care of, while harmful habits that cause damage to the environment must be addressed. The Vietnamese beauty urged everyone to work together to protect the environment.
Ha, born in 2004 in the southern province of Ben Tre, was a high school student in Ho Chi Minh City. She was crowned Miss Eco Vietnam 2022 last June.
The main motivation behind starting the pageant is to spread environmental awareness among the masses through the theme of economics and the environment.