The 19-year-old from Westmount, Que, was a 6-3, 6-3 winner in her debut on Centre Court at All England Club, which came after No. 2 Victoria Azarenka withdrew from the tournament due to a leg injury. Azarenka was scheduled to play on Centre Court.
Bouchard, last year's junior champion at Wimbledon, seemed composed throughout the match despite the increased attention. She broke Ivanovic for the fifth time to seal the victory, with the Serbian hitting into the net to end the 62-minute match.
"We only heard about the court change 15 minutes before the match," said Bouchard. "I was actually quite excited. It was crazy to play in front of a big crowd like this, I'm really happy. I was focusing on returns and neutralizing her first serve and I think I did that very well."
The rising teen star's only hint of nerves was when she failed to close out the match while serving with a 5-2 lead.
The Canadian improved to 21-14 on the season. She has posted some other big wins this year, including a third-round victory over U.S. Open winner Samantha Stosur last April at the Family Circle Cup in Charleston, S.C.
"I'm happy to be playing well again," Bouchard said. "After winning the juniors, Wimbledon feels like my second home."
Ivanovic reached world No. 1 status five years ago after winning the French Open. While seeded 12th, Ivanovic has often struggled at Wimbledon, however, failing to go beyond the fourth round in the last six years.
Bouchard entered the week 66th in the WTA rankings. She will next play Carla Suarez Navarro of Spain, a winner in three sets over Mirjana Lucic-Baroni of Croatia.
She becomes the first Canadian to reach the third round in the singles draw at Wimbledon since 2002.
Vancouver's Vasek Pospisil was also in action on Wednesday hoping to match that standard, playing against No. 20 Mikhail Youzhny of Russia.