The No.7 ranked Vondrousova pulled out of the tournament hours before her scheduled first round match against Russian qualifier Aliaksandra Sasnovich.
Taylor Townsend will take her place in the draw.
Meanwhile, sixth seed Jelena Ostapenko was broken while serving for the match at 5-2 in the third set and missed two match points in the next game before finally fending off Sorana Cirstea 2-6, 6-2, 6-4.
The 2017 Roland-Garros champion will next play Caroline Garcia, who beat Australian wildcard entry Taylah Preston 6-4, 1-6, 6-3.
“I feel like I was sleeping in the first set,” Ostapenko said.
“I’m not a morning person – I needed time to get into the match. When I start to take time and be a bit more calm, I play better.”
Czech qualifier Katerina Siniakova upset former world No.1 Karolina Pliskova 6-2, 6-1, winning 10 consecutive games after dropping serve early.
Two days after helping Germany win the United Cup final, Laura Siegemund needed almost three hours for her 6-7, 6-4, 6-4 win over seventh seed Liudmila Samsonova, recovering breaks in the second and third sets.
In the ATP tournament in Adelaide, Australia’s Jordan Thompson followed up his win over Rafael Nadal last week in the Brisbane International quarter-finals with a 6-2, 6-2 over Facundo Diaz Acosta to move into a second round match against No.4 seed Lorenzo Musetti.
Sloane Stephens, the 2017 US Open champion, was broken while serving for the match and then lost 6-4, 3-6, 7-6 to No.73 ranked Chinese qualifier Yuan Yue.
Stephens was coming off a second round exit last week at the Brisbane International, her first tournament since September.
Also in Hobart, sixth seed Sofia Kenin, who won the Australian Open and reached the Roland-Garros final in 2020, opened with a 6-3, 6-3 win over Greet Minnen.
No.9-seed Tatjana Maria was leading 6-1, 4-3 when Nadia Podoroska retired from their match.
Osaka vs Raducanu exhibition off
An exhibition match between Grand Slam champions Naomi Osaka and Emma Raducanu was scrapped after two time Australian Open champion Osaka withdrew as a “precautionary measure.”
The match was scheduled for Melbourne Park on Tuesday, the first of several exhibition matches planned on site in the week leading up to the season’s first major.
Osaka played her first competitive matches since late 2022 at the Brisbane International last week and is preparing for a return to the Grand Slam events.
The four time major winner gave birth to daughter, Shai, last July.