After S.J. Leeke departed for
Brynamman in 1925, Seion was without a minister for four years. D. Myrddin Davies commenced his ministry in 1929 and remained for seven years before moving to Bethel,
Aberystwyth. John Lewis was minister during the 1970s but moved to Drefach (Carmarthenshire) in 1978. The last minister at Seion was Gwilym Davies, who was inducted as minister of Seion together with Hengoed, Bryn Seion (Ystrad Mynach) and
Noddfa (Ynysybwl) in 1986. Seion remained an active church until the early 21st century. ==References==