I found two similar extracted marriage records for the couple, and a corresponding Civil Marriage, which means it was not an RC Marriage. One of the records is missing the day part of the date, but the other details match up ok.
Extracted Marriage Records (familysearch)
Groom's Name: John Greany
Bride's Name: Grace Green
Bride's Age: 19 (c1840)
Marriage Date: 20 Feb 1859
Marriage Place: Mallow, Cork
Groom's Father's Name: Patrick Greany
Bride's Father's Name: John Green
Groom's Marital Status: Single
Bride's Marital Status: Single
Reference Number: 11
(Familysearch Collection name : 'Ireland Marriages, 1619-1898' - the title is a little misleading, this collection includes marriages between 1864 and 1870 - and not all are included)
Civil Index Records Name: John Greany
Registration District: Mallow
Event Type: Marriage
Year: 1859
volume : 8 / page : 11
Name: Grace Greene
[same index details]
The matching reference page number (11) can help verify that it's the same civil record. You can order a marriage cert with the references mentioned on the Civil Index record - see :
Ordering Certs from GRO RoscommonShane