Harald Rein (born October 1, 1957, in Bochum) is a Swiss theologian and served as the seventh bishop of the Christian Catholic Church of Switzerland.

Since 1982, he has been active in the Christian Catholic Church of Switzerland, initially as a vicar in Möhlin, from 1983 to 1993 as a pastor in Obermumpf-Wallbach, and since 1993 in the parish of Zurich.

Since 2001, he served as the episcopal vicar of Bishop Fritz-René Müller, and after his resignation on March 1, 2009, he became the diocesan administrator.

[4] Harald Rein earned a Doctor of Theology degree from the University of Lucerne with a pastoral-theological thesis on highway churches.

As goals for his term as bishop, he mentioned the growth of the Christian Catholic Church of Switzerland,[10] which should not be achieved through proselytism but by addressing more church-distant people searching for a spiritual home.