MacMillan

"Good shot Lieutenant, I think you blew off his arm. Shock and blood loss'll take care of the rest."

MacMillan was a Scottish Special Air Service officer featured in Call of Duty 4: Modern Warfare.

Fifteen years prior to the events of Call of Duty 4: Modern Warfare, he was a captain in the SAS and the commander of a two-man SAS sniper team, including then-Lieutenant Price, who was assigned to assassinate Imran Zakhaev in a covert operation in Pripyat, Ukraine. After Price successfully injured Zakhaev, MacMillan and Lieutenant Price were compromised and forced to flee. MacMillan's leg was injured after a Russian gunship crashed and nearly killed him, so Price had to carry him the rest of the way to safety. Captain MacMillan is famous for his dense Scottish accent. During the missions One Shot, One Kill and All Ghillied Up, MacMillan instructs you throughout the levels.

He is voiced by actor Zach Hanks.

Trivia

 * If you look closely, MacMillan incorrectly holds the M21 as if it had a pistol grip, making it look like an M14 DMR.
 * In the lyrics of Deep and Hard, the song played in the credits, MacMillan is mentioned in the following phrase: "... This ones for MacMillian, 15 years you had relaxing..." These lyrics point to the fact that he retired as a Captain, probably because of his leg injury and/or age.
 * Before you get to the main menu, a cutscene plays, saying "50,000 people used to live here, now it's a ghost town." If you listen closely, Zach Hanks does not voice MacMillan here. It sounds more like Gaz. Furthermore, when MacMillan says this in All Ghillied Up, he says "50,000 people used to live in this city", the voice was possibly changed for international audiences as the developers thought they wouldn't understand the accent.
 * In sniping missions in which the player controls Soap, Captain Price will occasionally say, "Good job, MacMillan would be impressed."
 * There is speculation that MacMillan is named after the McMillan Tac-50 sniper rifle, which was used to get the farthest recorded sniper kill.
 * If you look closely when MacMillan gets hit with the fallen gunship on One Shot, One Kill, the helicopter blades may or may not appear to touch Macmillan. This may be just a animation error, or it might just be portrayed as him falling while running away, and breaking or badly spraining his leg in the process. It was once stated that the helicopter scene had taken a considerable amount of time to create, and the developers would most likely not overlook it.
 * Strangely, in some trailers he is seen with a suppressed M4A1 and others with his M21. It might be he was originally supposed to have an M4 but they changed it and gave him a sniper rifle.
 * Players have found rather funny, unused dialogue within the game files, heard here.
 * When MacMillan knocks the enemy down with the stock of his M21 during All Ghillied Up, he sometimes runs too far away to hit him, but still the enemy falls down, although he really didn't get hit.
 * MacMillan actually says "Aw fuck!" when he gets hit by the helicopter, although the subtitles read "Aw crap!" This makes him the first character in the series to use the word.
 * There is a humorous reference in Arby n the Chief Episode Two- "Recon" where Master Chief makes a ridiculous plan with multiple video game characters to get his Recon Armor. Characters included are Solid Snake, MacMillan, and also a team of invisible ninjas!
 * MacMillan is one of the most liked characters in the game due to his stealthy nature, Scottish accent, and epic dialogue, specifically, "...we'll be impossible to spot in our ghillie suits."