  The Orion OB1 Association, at a distance of roughly 400 pc and spanning over
~200 deg^2 on the sky, is one of the largest and nearest OB associations. With
a wide range of ages and environmental conditions, Orion is an ideal laboratory
for investigating fundamental questions related to the birth of stars and
planetary systems. This rich region exhibits all stages of the star formation
process, from very young, embedded clusters, to older, fully exposed young
stars; it also harbors dense clusters and widely spread populations in vast,
low stellar density areas. This review focuses on the later, namely, the
low-mass (M ~< 2 Mo), pre-main sequence population spread over wide spatial
scales in Orion OB1, mostly in the off-cloud areas. As ongoing studies yield
more complete censa it becomes clearer that this "distributed" or non-clustered
population, is as numerous as that located in the molecular clouds; modern
studies of star formation in Orion would be incomplete if they did not include
this widely spread population.
