The single was written by Thomas and produced by Matt Serletic. Although he had guest starred on Santana's "Smooth" years before this song, "Lonely No More" is notable for being the proper solo debut single of Thomas. Unlike the singles he had released in Matchbox Twenty or even “Smooth” (which had more of a Latin rock feel), "Lonely No More" deviates by not containing a strong rock sound, and instead on focusing on a more pop like feel. Starting over a series of chordless industrial rhythmic beats, Thomas explains to a prospective romantic interest over a Latin beat why he is not exactly comfortable heading into a relationship with her at the moment. Although she seems to know what to say to him, he points out that words are only words. She needs to show him something else, or even swear allegiance to reassure his insecurities. To explain exactly how hurt he has been in previous relationships, Thomas belts, "I don't wanna be lonely no more/I don't wanna have to pay for this/I don't want to know the lover at my door/Is just another heartache on my list". The song was nominated for Best Male Pop Vocal Performance at the 2006 Grammys.
The music video of "Lonely No More", directed by Joseph Kahn, does not follow the plot of the song closely and does not have a clear plot in the video. Instead, it focuses on the visual look of the video especially with its special effects which emulate a Rubik's Cube effect. Thomas can be seen in various scenes as they shift or fold violently into each other (while Thomas remains immobile) from being his bedroom, to a nightclub, and to an office. Although the shifting scenes and objects seem to move by themselves, at one point Thomas can be physically prodding them to move. The video does try to incorporate some elements of the loneliness of "Lonely No More" by showing Thomas looking forlorn in a paparazzi scene and expressing mixed feelings about some girls in the video.