This report details the Accelerator Communication and Outreach workshop that was carried out in the context of milestone MS05 of the I.FAST project. This report represents the completion of said milestone. The ACO workshop was organised under the requirements of Task 2.2 with the goal to engage the network of communication officers from the major institutes of the European accelerator community in knowledge-sharing and in developing a synergistic communication and outreach strategy. The ACO workshop was successfully held on March 20 – 21, 2025, at CERN with 15 participants from accelerator facilities around Europe. The report covers the details of the workshop and the outcomes from the discussions that were held.