"I... Can't... Believe... This... You guys have absolutely lit up my world. Thank you," the country pop star tweeted Wednesday morning.
According to Nielsen SoundScan figures, "Speak Now" sold 1,047,000 copies since it was released last week. That's slightly higher than the 1,006,000 posted by Lil Wayne's "Tha Carter III" in 2008.
"Speak Now" is the 20-year-old's third album. Her self-titled debut and her sophomore album, 2008's "Fearless," both went multiplatinum.
The Associated Press contributed to this report.