Fr. Rocky: Reiki is not Catholic. The doctrinal committee of the U.S. Conference of Catholic Bishops studied this question in 2009 and provided an answer several pages long. I copied some lines from that document:
“Without justification either from Christian faith or natural science, however, a Catholic who puts his or her trust in Reiki would be operating in the realm of superstition, the no-man’s land that is neither faith nor science. Superstition corrupts one’s worship of God by turning one’s religious feeling and practice in a false direction.”
The document concludes with this statement: “Since Reiki therapy is not compatible with either Christian teaching or scientific evidence, it would be inappropriate for Catholic institutions, such as Catholic health care facilities and retreat centers, or persons representing the Church, such as Catholic chaplains, to promote or to provide support for Reiki therapy.” The document was signed by eight bishops and archbishops.