Simpson wrote this song with Nashville songwriters Brett James and Hillary Lindsey. US Weekly reported that during her March 12, 2009 concert in Phoenix, Arizona, at the Cricket Wireless Pavilion Simpson explained this was written for "a guy that I couldn't get over." She added: "After I wrote that song, I was mad at myself for being so weak and I got over that guy!"
"Thinking About You" was the ninth track from Calvin Harris' 18 Months album to enter the UK singles Top 10. No other artist has obtained so many hits from one LP - Michael Jackson was the previous record holder with seven Top 10 tunes from both his Bad and Dangerous sets.