Research facilities driven by high-power proton beams have an impressive track record of promoting scientific and technological innovation to the direct benefit of the knowledge-based economy. The US has a track record of excellence in the provision of such facilities at both the energy and at the intensity frontiers. The UK also has an impressive track record, contributing at the intensity frontier. Both the UK and the US are key stakeholders of CERN which, with the recent closure of the FNAL Tevatron, is the world's energy-frontier laboratory for particle physics. Not only do advances in accelerator technology make it possible to conceive of entirely new accelerator facilities capable of expanding the horizons of the world's scientists, but, it is now possible to define the R&D path to the proton-accelerator based facilities that will revolutionise the health-care, clean-energy, and security agendas. R&D programmes designed to deliver the key technologies and systems are underway in both the UK and the US and, while communication, cooperation, and in some cases collaboration, between the various projects has been effective at an individual level, there is a great potential benefit in developing a more strategically-coordinated approach. Not only would greater cooperation substantially strengthen the domestic programmes, appropriate development of collaborative projects would allow the benefits to the science, health-care, energy, and security agendas to be delivered more rapidly. The "Proton accelerators for science and innovation" workshop that will be held at the Fermi National Accelerator Laboratory from the 12th to the 14th January 2012 will bring together the leading members of the user, developer, and 'consumer' communities from the UK and the US to review and discuss the issues outlined above. It is our ambition that this workshop will lay the foundations on which an appropriately coordinated programme for the development of the proton accelerators of the future can be built.