Malachi O'Brien (12 June 1867 – 2 August 1953) was an Irish Gaelic footballer.
After leaving school at the age of fourteen he found employment with Cannock's department store in Limerick.
O'Brien later spent a short time with Clerys in Dublin before emigrating to the United States, where he remained until 1929, before returning to Ballinvreena.
After moving to Limerick, O'Brien first played competitive Gaelic football with the Commercials club, winning three successive county senior championship medals between 1887 and 1889.
He won his sole All-Ireland medal that year as Limerick defeated Louth in the final.