Simon David Brown is the oldest child of seven, and often acts as the ringleader to his siblings. This usually when he is protective of them and bosses them around saying they have to do what he tells them to do.
Simon is intelligent, mischievous, sly and charismatic. He is a natural leader and appears to be the chieftain of the Brown children, causing the expulsion of several nannies. He is an extremely brave individual, unafraid to stand up to others. He is also hot-tempered as shown on one occasion where he openly snaps at his own father about the latter never listening until he realizes that his anger caused his family to have problems. He apologized to his father that he and his siblings are the problem.
- Thomas Sangster (who portrayed Simon) had his fifteenth birthday while filming.
- Skandar Keynes, whom portrayed Edmund Pevensie in the Chronicles of Narnia, tried out for this role.
- "I NEVER say 'please'!"
- "Pleased to make your acquaintance. I'm Oglington Fartworthy." - "Introducing" himself to Nanny McPhee.
- "We will never want you."
- "It doesn't matter. We are getting rid of her tomorrow."