Career
Derry
Duffy is a product of the Derry City youth team and made his first appearance for the senior team at Richmond Park on 3 September 2012 as a second-half substitute in a 3-0 defeat to Street Patrick"s Athletic. As a 19-year-old Duffy scored against Aberystwyth Town and Shakhtyor Salihorsk in the Europa League and netted a hat-trick in July on his 20th birthday in a league match against University College Dublin. In October 2014 it was reported that he had signed a two-year contract extension with Derry. Celtic
In February 2015 he was transferred to Scottish club Celtic.
Duffy has not played in the first team for Celtic but impressed in the Development squad.
In July 2015, he was loaned to Alloa Athletic on a six-month deal. Alloa (Loan)Editorial
At the start of 2016 Duffy was reported to be extending his stay at Alloa until the end of the 2015/16 season.
In February 2016 Duffy scored his first goal for Alloa. Michael Duffy was called up to the Home-Based Republic of Ireland Under-18 by Paul Doolin on 1 February 2012 for a friendly game against Wales.
On 15 February, he played the entire game in a 2–1 defeat at Ferrycarrig Park, Wexford.
Duffy has since represented Northern Ireland at Under-19 and Under-21 level He made his debut for the Under-21 team on 9 September 2014 in a 4–1 defeat against Serbia at Shamrock Park, Portadown.
