Or or OR may refer to:

Arts and entertainment
Film and television
"O.R. ", a 1974 episode of M*A*S*H
Or (My Treasure), a 2004 movie from Israel (Or means "light" in Hebrew)

Music
Or (album), a 2002 album by Golden Boy with Miss Kittin
O*R, the original title of Olivia Rodrigos album Sour, 2021
"Or", a song by Israeli singer Chen Aharoni in Kdam Eurovision 2011
Or Records, a record label
Organized Rhyme, a Canadian hip-hop group featuring Tom Green

Businesses and organizations
Or (political party) (lit.
Rho(D) immune globulin (RhIG) is a medication used to prevent RhD isoimmunization in mothers who are RhD negative and to treat idiopathic thrombocytopenic purpura (ITP) in people who are Rh positive. It is often given both during and following pregnancy. It may also be used when RhD-negative people are given RhD-positive blood. It is given by injection into muscle or a vein. A single dose lasts 12 weeks.Common side effects include fever, headache, pain at the site of injection, and red blood cell breakdown. Other side effects include allergic reactions, kidney problems, and a very small risk of viral infections. In those with ITP, the amount of red blood cell breakdown may be significant. Use is safe with breastfeeding. Rho(D) immune globulin is made up of antibodies to the antigen Rho(D) present on some red blood cells. It is believed to work by blocking a persons immune system from recognizing this antigen.Rho(D) immune globulin came into medical use in the 1960s. It is on the World Health Organizations List of Essential Medicines. It is made from human blood plasma. Medical uses
In a pregnancy where the mother is RhD negative and the father is RhD positive, the probability of the fetus having RhD positive blood is dependent on whether the father is homozygous for RhD (i.e., both RhD alleles are present) or heterozygous (i.e., only one RhD allele is present). If the father is homozygous, the fetus will necessarily be RhD positive, as the father will necessarily pass on a Rh D positive allele.