This workshop is a successor and follows up to similar workshops held at CERN in April 1999, at Fermilab in June 2001, in Montauk 2003, and at CERN in March 2013. A lot of progress has been made since the last workshop at CERN in the study of the beam-beam effects in colliders such as the LHC. Meanwhile, there are also beam-beam challenges in future colliders such as the next generation nuclear physics electron ion collider (EIC). The purpose of this workshop is to bring experts in this field to review progress in beam-beam studies of the current and past colliders and to discuss potential beam-beam issues and solutions in the future colliders.