A Master of Science (; abbreviated M.Sc., MSc, M.Sci., M.Si., Sc.M., M.S., MSHS, MS, Mag., Mg., Mgr, S.M., or SM) is a postgraduate academic master's degree awarded by universities in many countries. The degree is typically studied for in the sciences including the social sciences.

SM, Sm, sm, or .sm may refer to:

• SM Supermalls, a chain of shopping malls in the Philippines
• S.M. Entertainment, a South Korean talent agency, classical music, dance
• SM Prime Holdings, a Philippine retail operator
• Savoia-Marchetti, an Italian aircraft company
• SM-liiga, the top professional ice hockey league in Finland
• SM-sarja, the former top level of ice hockey in Finland
• Service Merchandise, an online retailer
• Syndicat de la Magistrature, a French union
• Society of Mary Marianist Fathers (Institute of Consecrated Life) Societas Mariae

Sadomasochism broadly refers to the receiving of pleasure—often sexual—from acts involving the infliction or reception of pain or humiliation. The name originates from two authors on the subject, Marquis de Sade and Leopold von Sacher-Masoch. A subset of BDSM, practitioners of sadomasochism usually seek out sexual gratification from these acts, but often seek out other forms of pleasure as well. While the terms sadist and masochist specifically refer to one who either enjoys giving pain (sadist), or one who enjoys receiving pain (masochist), many practitioners of sadomasochism describe themselves as at least somewhat of a switch, or someone who can receive pleasure from either inflicting or receiving pain.

The Society of Mary, a Roman Catholic Marian Society, is a congregation of brothers and priests called The Marianists or Marianist Brothers and Priests. The Society was founded by Blessed William Joseph Chaminade, a priest who survived the anti-clerical persecution during the French Revolution. The Society is one of the four branches of the Marianist Family. Along with the other branches, the Marianist Brothers and Priests look to Mary as a model of faith and spirituality. They believe that the best ways to live a spiritual life are to share their faith with others, work with the poor, and educate and nourish the mind, the body, and the soul.