The 1999 Oklahoma State Cowboys football team represented Oklahoma State University as a member of the Big 12 Conference during the 1999 NCAA Division I-A football season. Led by fifth-year head coach Bob Simmons, the Cowboys compiled an overall record of 5âÂÂ6 with a mark of 3âÂÂ5 in conference play, placing fifth in the Big 12's South Division. Oklahoma State played home games at Lewis Field in Stillwater, Oklahoma.