The FAI Cup 1927–28[A] was the seventh edition of Ireland's premier cup competition, The Football Association of Ireland Challenge Cup or FAI Cup.
The tournament began on 7 January 1928 and concluded on 17 March with the final held at Dalymount Park, Dublin.
An official attendance[B] of 25,000 people watched amateur side Bohemians defeat defending champions Drumcondra to secure a quadruple of trophies.
^ From 1923 to 1936, the FAI Cup was known as the Free State Cup.
^ Attendances were calculated using gate receipts which limited their accuracy as a large proportion of people, particularly children, attended football matches in Ireland throughout the 20th century for free by a number of means.