The four-time Olympic medallist posted a time of one minute 58.98 seconds, leading her heat.
Haughey said she is not yet at her peak, after a break earlier in the year and recovery from a back injury.
“I’m satisfied with my performance. Because it’s just the heats, I knew finishing in the top three of my group gave me a great chance of advancing,” she said.
“I haven’t competed in a large-scale international event for several months, so I’m hoping to regain my routine. As I begin my other events at the Games, I hope to find my rhythm.”
Teammate Gilaine Ma also qualified, finishing with a time of two minutes 0.78 seconds, edging out Zhejiang’s Mao Yihan by 0.07 seconds to secure the final semifinal spot.
“I’m satisfied with how I performed. My result is close to my personal best time of two minutes 0.66 seconds,” Ma said.
“My goal is to swim close to my personal best or break my record. Since I don’t often join domestic competitions, I don’t really know how others perform, so I focus on my own race.”
However, Wang Xintong placed 46th and did not advance.
The women’s 200 metres freestyle semifinals will take place at 8:04pm.
On the men’s side, Tsui Yik-ki, Adam Mak and Nicholas Cheung also moved on to the top 16 in the 50 metres breaststroke.
But Wang Yi-shun exited the 200 metres butterfly after finishing 40th overall.
