The 2026 R-matrix workshop—held at Oak Ridge National Laboratory (ORNL), Oak Ridge, TN, USA on July 13–17, 2026—will focus on several topics specific to the  phenomenological R-matrix analysis of nuclear reactions with particular emphasis on  neutron induced reactions. Among these,
• theoretical advances such as breakup reaction models, fission channel in the R-matrix framework, secondary gamma reactions, relativistic R-matrix models, primary gammas, polarization observables,
• experimental techniques,

A one-week collaborative meeting bringing together experts in nuclear physics and stellar astrophysics to shape shared research priorities and draft a proposal for future collaborations and meetings.