<P> Francis, played by Christopher Masterson (119 episodes), is the oldest of the brothers, whom Malcolm often looks up to . It is revealed in the episodes "Sleepover" and "The Bots and the Bees" in season one that Francis was a breech birth, and in "Flashback" in season 2, that Lois was in labor with him during her and Hal's wedding . A rebel from birth, showing signs of Attention - Deficit Hyperactivity Disorder and Conduct Disorder, he was exiled to Marlin Academy by Lois for his behavior before eventually emancipating himself to run away from the Academy to work in Alaska, incurring his mother's wrath . Upon moving to Alaska, he marries a local woman named Piama, who is about one year older than him, and had previously been married briefly, and whom Lois doesn't like . In the series finale, Hal discovers that Francis has taken a job with Amerysis, and Francis admits he likes sitting at a desk sorting computer data . However, he also admits that he has no intentions of telling Lois about the job and enjoys torturing her by telling her that he's still unemployed . </P> <P> Malcolm, portrayed by Frankie Muniz (all 151 episodes), is the protagonist of the series . He is Three years younger than his oldest brother Francis, one 1 / 2 years younger than his older brother Reese, five years older than his younger brother Dewey, and about 15 years older than his youngest brother Jamie . In the first episode of the series, he is discovered to be a child prodigy and immediately moved from his regular class into the' Krelboynes', a class for gifted students . Despite his high intelligence, he still gets into mischief either alongside or working against his brothers (in particular, Reese), although he becomes more self - absorbed and egotistical in the later seasons as he goes through puberty . Malcolm, like Reese, is not very popular . However, he has had a number of girlfriends during the series run . Even though he is very intelligent, Malcolm has a short temper, can be easily manipulated and also has problems containing his opinion about himself . Malcolm also occasionally serves as the voice of reason, and does have a conscience, (for instance, despite emotionally manipulating a grieving Hal to buy him a car in the episode "Hal Grieves," when the time comes to make the purchase he finds he can't go through with it). In the series finale, it is revealed that Lois intended him to have a hard life, knowing that he is destined to assume the role of President of the United States; she wants him to remember where he came from to get there and try to help families like his own when he assumes the office . Malcolm eventually comes to terms with his future, after being unable to tell Lois he can't do it . In the series finale, Malcolm begins taking classes at Harvard University . Throughout the series, Malcolm frequently breaks the fourth wall and talks to the viewer about either the current situation or giving exposition about past events . </P> <P> Lois, played by Jane Kaczmarek (146 episodes), is Francis, Reese, Malcolm, Dewey, and Jamie's angry and temperamental mother . She is an overbearing control freak despised by the neighbors to the point that they refuse to invite her to their gatherings, revealed in "Mono". Unlike Malcolm, Lois isn't bothered by it and tries her best to blend in with it . She was revealed to be a charming and a nurturing mother while Francis was little, but toughened up . She is also always stubbornly right, to the point of being unable to say that she was wrong . It was also shown that she is overbearing and mad as a result of her children's bad behavior, and not her pure hate . At the series finale, Lois is revealed to be pregnant with a sixth child (actually twins). Her unfairness and behavior also come from her miserable childhood, living with a tough mother and an uncaring father (both of whom favored her younger sister, Susan). </P> <P> Reese, played by Justin Berfield (all 151 episodes), is the second oldest of the sons . He is two years younger than his older brother Francis, one year older than his younger brother Malcolm, six years older than his younger brother Dewey, and about 16 years older than his youngest brother Jamie . It was revealed in the episode "Flashback", in season 2, that Reese has been vicious from the womb, so vicious in fact that when he kept kicking Lois during labor, she pushed him out by force . A complete moron from birth, Reese is the worst - behaved of the brothers . Reese is inclined to beat up the Krelboynes . He is intimidated by certain students, including Ira, a dumb jock at school . Despite his violent, idiotic nature, Reese is a culinary prodigy, after finding that he has a talent and genuine love for cooking and baking . He is also the favorite grandson of his grandmother Ida, who taught him the importance of having patsies . In the series finale, Reese moves in with Craig Feldspar and is a janitor at his alma mater North High . </P>

Who played the babysitter in malcolm in the middle