She Used to Be Mine may refer to:

• "She Used to Be Mine" (Brooks & Dunn song), 1993
• "She Used to Be Mine" (Sara Bareilles song), 2015
• "My Best Friend's Girl" (song), 1978, by The Cars

• Psychological theory
• Psychological therapies
• Psychological therapy
• Psychological Trauma: Theory, Research, Practice, and Policy
• Psychological Warfare Department
• Psychologists prescribing law
• Psychology and Aging (journal)
• Psychology Building
• Psychology experiment
• Psychology from an Empirical Standpoint
• Psychology in Russia (journal)
• Psychology in Russia: State of the Art
• Psychology In The Book of Healing
• Psychology In The Book of Healing of avicenna
• Psychology in the Philippines
• Psychology in the Schools
• Psychology (journal)
• Psychology Maziwisa
• Psychology of collecting
• Psychology of criticism
• Psychology of Crowds (book)
• Psychology of dance
• Psychology of Dance
• Psychology of disenfranchisement
• Psychology of eating meat