Michael David Capellas (born August 19, 1954) is an American executive in the computer and telecommunication industries. Capellas served as chairman and CEO of First Data Corporation, acting CEO of Serena Software, chairman and CEO of Compaq Computer Corporation until its merger with Hewlett-Packard where he became president of the post-merger company briefly, and president and CEO of WorldCom (later MCI) where he led its merger with Verizon.