This is a collection of papers presented at the Topical Meeting on Optical BistabiJity (OB3) held December 2-4,1985 in Tucson, Arizona. The increase in attendance to almost 200 shows that interest continues to grow in the sub ject of optical bistability (OB) and its wider implications both in application to "optical digital computing" and to basic physics, notably instabilities and spatial effects. The maturing of the field is evidenced by the fact that the number of experimental papers has caught up with the number of theoretical ones. These trends were already apparent in OB2 and the 1984...