"I can only hope that everyone could feel my love for this country and that the true spirit of its anthem still came through," she said in a statement after the performance, The Associated Press reports.
When she was supposed to sing the line "O'er the ramparts we watched, were so gallantly streaming," she instead repeated an earlier line, with a slight variation.
She sang, "What so proudly we watched at the twilight's last reaming," repeating and mangling an earlier lyric, with the word 'watched' instead of 'hailed' and 'reaming' instead of 'gleaming.'
The mistake immediately set social networks abuzz with people commenting on the error.
Aguilera, who took the stage in a black dress, was returning to the Super Bowl after being one of the performers during the halftime show in Atlanta in 2000.
After it was announced that Aguilera would be singing the national anthem for the 2011 Super Bowl, she said in a news release that she had been performing the song since she was 7 and was "excited to be part of such an iconic event."