OB or Ob may refer to:
Obsessive–compulsive disorder (OCD) is a mental disorder where people feel the need to check things repeatedly, perform certain routines repeatedly (called "rituals"), or have certain thoughts repeatedly.
Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which may contain data, in the form of fields, often known as attributes; and code, in the form of procedures, often known as methods.
Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have a negative effect on health.
Objective-C is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language.
The observable universe is a spherical region of the Universe comprising all matter that may be observed from Earth at the present time, because light and other signals from these objects have had time to reach Earth since the beginning of the cosmological expansion.
Obergefell v. Hodges, 576 U.S. ___ (2015) (/ˈoʊbərɡəfɛl/ OH-bər-gə-fel), is a landmark United States Supreme Court case in which the Court held in a 5–4 decision that the fundamental right to marry is guaranteed to same-sex couples by both the Due Process Clause and the Equal Protection Clause of the Fourteenth Amendment to the United States Constitution.
Objectivism is a philosophical system developed by Russian American writer Ayn Rand (1905–1982). Rand first expressed Objectivism in her fiction, most notably The Fountainhead (1943) and Atlas Shrugged (1957), and later in non-fiction essays and books.
Oberlin College is a private liberal arts college in Oberlin, Ohio. The college was founded as the Oberlin Collegiate Institute in 1833 by John Jay Shipherd and Philo Stewart.
Obesity in the United States has been increasingly cited as a major health issue in recent decades. While many industrialized countries have experienced similar increases, obesity rates in the United States are among the highest in the world.