The Belfast man was named this week as one of a dozen aides to the New York Police Department Commissioner and will be introduced officially at the installation of Kelly in mid-January.
McAllister said he was surprised, delighted and flattered to be selected for the post.
The aides for the 2010 parade were named by parade chairman John Dunleavy at a meeting of parade delegates held in the New York Athletic Club in Manhattan.
According to the parade committee, aides to the grand marshal are chosen annually by the parade's participating organizations "in recognition for their outstanding service to the Irish American Community of New York."
The selection as an aide. The committee said, "is acknowledgement for years of unselfish dedicated and distinguish service to the community and for outstanding dedication and contribution to Irish faith, culture and heritage by an individual."
"We are extremely happy to recognize outstanding individuals and this year's aides are exceptional," said parade secretary, Hilary Beirne.
The aides are: James Barnes, Knights of St. Patrick; Matthew Devine, New York County; John W. Hyland, Bronx County; Catherine McCarthy, Queens: Bridie Mitchell, Kings County; Judge Michael J. Brennan, Richmond County; Michael Byrne, Nassau County; Thomas Jordan, Suffolk County; Cathleen Courtney, Westchester County; Rose Veronica Moroney, Rockland County; Edmund Burke, Orange County; Buddy Sullivan, Grand Council of Emerald Societies, Malachy McAllister, United Irish Counties, and Terrance McAdams who is an aide at large.
"All of the grand marshal aides have been chosen by our participating organizations and we are delighted with each and every one of them," said John Dunleavy.
McAllister marked 21 years away from his native Belfast this week. His family fled after his home was attacked by loyalist gunmen. McAllister is still battling to secure full legal residence in the U.S. for himself and his family.