"Thinking of You" is the fourth single of Katy Perry from her 2008 album One of the Boys. It is one of three tracks from the album written solely by Perry and the first single since "Ur So Gay" to be produced by another producer (Butch Walker), other than Dr. Luke. Perry performed the song as the official single of her hit album, One of the Boys for the first time on MuchMusic HQ's MuchOnDemand on December 15, 2008.
"Thinking of You" also features on the compilation CD's Now That's What I Call Music! 72 and Now That's What I Call Music! 30 of the UK and US respectively. The song was included in the international soundtrack to India, a Love Story, an Emmy-winning Brazilian soap opera, which helped to propel "Thinking of You" up the charts in both Brazil and Portugal, where the soap opera is shown.
"Thinking of You" debuted in the Bubbling Under Hot 100 chart at 5, a couple of weeks later it finally charted in the Hot 100 at 79, and within three weeks it rose to its current peak position of 29 and stayed in this position for 3 consecutive weeks. It has been Katy's worst performing single on the US charts. The song debuted on the Canadian Hot 100 at 58, on the following week it rose 24 places to its current peak position of 34. In Ireland the song charted at 38. The song debuted at 63 in the UK despite minimal airplay on music channels and radio. The song peaked at #27 on the UK Singles Chart.
There are two video versions for this song. The first music video was released in 2007 and surfaced onto YouTube in May 2008. The video includes multiple rooms, including a white room with Perry that suggests violence (e.g., red wine), a dark room with an unhappy Perry in an unsatisfactory relationship, and a cloudy location. The video uses a cross-cutting technique that compares the two relationships: one with Perry reminiscing and another showing regret. The video ends with the revelation that Perry literally stabbed a man in the back in the white room. Perry stated in an interview that the aim of the video was never to get a commercial release, but that it is just a simple video "made by a friend".
Perry revealed on her blog that she had already started filming a second and official music video in the first week of December 2008, directed by Melina. The video premiered exclusively on iTunes on December 23, 2008. The music video is presented as a flashback montage with a young woman (played by Perry) whose lover is killed in France during the Second World War. Perry is clearly not pleased with her new love and longs for her deceased lover to be back. It features actor Matt Dallas as Perry's true love and model Anderson Davis as Perry's second love in the video. The music video for song has received more than 18 million views on YouTube.