At the 2012 World Championships which took place in Meares' home country of Australia in Melbourne, Meares was favourite for three gold medals. In the team sprint Meares won silver as Germany set two world records in the event. In qualification for the individual sprint Meares broke the world record for the flying start 200 metres. Meares completed her four laps in just 10.782 seconds shaving 11 thousands of a second off Simona Krupeckaite's mark. In the semi final Meares faced her old rival Pendleton. Pendleton clashed with the Australian in their first heat and ended up on the floor before Meares was relegated from the second for going outside of her lane. In the decider Pendleton won in a photo finish, with Meares settling for bronze after defeating Lyubov Shulika. In the keirin, Meares won both her qualifying races before reaching the final, where she held off Russian Ekaterina Gnidenko and German Kristina Vogel to win the first of two world championships in Melbourne. Meares set her second world record of the championships in her final event. Meares recorded 33.010 seconds to break the record by .286 of a second which was previously held by Simona Krupeckaite. With the time Meares won her second title of the championships and equaled Felicia Ballanger's record of ten world titles.