In genetics, translocation refers to a phenomenon in which part of a chromosome breaks off and becomes attached to a different (non-homologous) chromosome. Translocations can be reciprocal, in which two different chromosomes essentially swap parts. An individual with this chromosomal abnormality still has all the right genetic material and will usually have a normal phenotype, but, because the chromosomes have trouble pairing during meiosis, will usually produce some fraction of inviable gametes.

An individual having one or more pairs of homologous chromosomes, one member of which is normal, and the other member of which is the result of a translocation, is called a translocation heterozygote.