Cast

Will Smith as Captain Steven Hiller: An assured United States Marine Corps F/A-18 pilot at the forefront of the human resistance counter-offensive. His ambition before the alien attack is to join NASA's astronaut training program. Devlin and Emmerich had always envisioned an African-American for the role,[5] and specifically wanted Smith after seeing his performance in Six Degrees of Separation.[6] Jeff Goldblum as David Levinson: An MIT-educated computer expert who is a chess enthusiast and environmentalist, working as a satellite technician for a cable television company in New York City when he discovers the aliens' invasion plot. He still has strong feelings for his ex-wife and later formulates a plan to defeat the invaders.

Bill Pullman as President Thomas J. Whitmore: A former Persian Gulf War fighter pilot and current President of the United States whose approval ratings early in the film indicate the nation's dissatisfaction with his performance. To prepare for the role, Pullman read The Commanders by Bob Woodward and watched the documentary film The War Room.[7]

Margaret Colin as Constance Spano: The White House Communications Director and David's ex-wife. Though she still loves David, she feels that he is underachieving, and divorced him to pursue her career alongside President Whitmore. Robert Loggia as General William Grey: A United States Marine Corps general who is the Chairman of the Joint Chiefs of Staff, and one of President Whitmore's most trusted advisors. Loggia modeled the character after generals of World War II, particularly George S. Patton.[8]

Randy Quaid as Russell Casse: A widowed, alcoholic crop duster and veteran Vietnam War pilot who claims to have been an alien abductee ten years prior to the events of the film. He struggles to care for his three children. At the end of the film, he sacrifices himself to destroy an alien destroyer, gaining the admiration of his eldest son, who previously held little respect for him. James Duval as Miguel Casse,[9] Russell's eldest son. He was not very respectful of his alcoholic father (even calling him "Russell"), but after Russell sacrifices himself to save everybody, Miguel thinks better of him.

Judd Hirsch as Julius Levinson: David Levinson's father. The character was based on one of Devlin's uncles.[10]

Mary McDonnell as Marilyn Whitmore: The wife of President Whitmore. She is wounded while fleeing the destruction of Los Angeles and later dies from internal bleeding.

Vivica A. Fox as Jasmine Dubrow: A single mother, Steve's girlfriend and exotic dancer. She searches for fellow survivors in the aftermath of the Los Angeles attacks, finding the First Lady in the process. James Rebhorn as Albert Nimziki: The Secretary of Defense and former director of the CIA. He advocates the use of nuclear weapons in response to the alien threat. Rebhorn described the character as being much like Oliver North.[11] The character's eventual firing lampoons Joe Nimziki,[12] MGM's head of advertising and reportedly accounted for unpleasant experiences for Devlin and Emmerich when studio executives forced recuts of Stargate.[13] Harvey Fierstein as Marty Gilbert: David's boss, who is killed during the alien attack on New York City. Adam Baldwin as Major Mitchell: A United States Air Force officer who is the commanding officer at Area 51. Brent Spiner as Dr. Brackish Okun: The unkempt and highly excitable scientist in charge of research at Area 51. He is later killed by a captured alien.[14] Devlin, who is open to the idea of bringing Dr. Okun back in the event of a sequel, later implied the character is merely in a coma.[15] The character's appearance and verbal style are based upon those of visual effects supervisor Jeffrey A. Okun, whom Emmerich had worked with on Stargate.[16 Harry Connick, Jr. as Captain Jimmy Wilder: The best friend of Steve and fellow pilot, killed while fleeing a failed attack on an alien spacecraft. Connick took over the part for Matthew Perry, originally cast in the role.[17] Kiersten Warren as Tiffany: Jasmine's exotic dancer co-worker who is killed during the alien attack on Los Angeles.