The family adventure took in $26.8 million , edging out "Tyler Perry's Madea's Big Happy Family," which debuted a close second with $25.8 million.
Reese Witherspoon and Robert Pattinson's circus romance "Water for Elephants" premiered in third-place with $17.5 million.
Russell Brand and James Marsden's "Hop" snagged the No. 4 spot, and "Scream 4" rounded out the top five with $7.2 million.
1. "Rio," $26.8 million.
2. "Tyler Perry's Madea's Big Happy Family," $25.8 million.
3. "Water for Elephants," $17.5 million.
4. "Hop," $12.5 million.
5. "Scream 4," $7.2 million.
6. "African Cats," $6.4 million.
7. "Soul Surfer," $5.6 million.
8. "Insidious," $5.4 million.
9. "Hanna," $5.3 million.
10. "Source Code," $5.1 million.
The Associated Press contributed to this report.