This handbook emphasizes a sex-positive approach to human sexuality counseling, providing 25 chapters by counseling and other specialists from the US, who avoid pathologizing or discriminating against sexual behaviors and expressions that are not heteronormative, reproduction-focused, or cisnormative. They emphasize a strengths-based, developmentally appropriate, psychoeducational, and sex-positive approach, with examples of evidence-based, sex-positive, and practical treatment planning and implementation. Chapters address the foundations of the approach, including current issues in mental health and the difference between a sexual wellness and a medical framework; the history of sex, including cultural taboos, the impact of religion, and cultural differences in sexual norms, as well as the politics of sex; ethics and professional pitfalls; physiological and psychological aspects, including the physiology of sex, the role of the brain in sex and desire, the role of orgasm, and societal messages about sex and sexuality; and aspects of attraction, sexual orientation, and gender, including gender diversity. They then address sexual wellness, including the benefits of masturbation, the impact of chronic illness and pain on sexual attitudes and desire, working with individuals with sexually transmitted infections, and assisting survivors of sexual harassment, assault, trauma, and trafficking; sexual agency, including sexuality in later life, disability, race and ethnicity, and religion; approaches to sexual divergence like kink, swinging, BDSM, fetishes, and consensual objectification, as well as sexual addiction and sexual divergence in relation to the paraphilia section of the Diagnostic and Statistical Manual of Mental Disorders; relationship aspects, including love, dating, hookup culture, and infidelity; and sex education and counselor training.