The Senior Citizen Centre is as its name implies, a senior citizen organization in Greg's state. In The Third Wheel, when the Valentine's Day Dance was going to start, the seniors piled up into the gym. One of the teachers, Mrs Sheer told them that the gym had been reserved two weeks ago for the Valentine's Day Dance. However, the senior's claimed to have booked it two months ago for a meeting and they had the paperwork to prove it. So they divided the gym in to two parts, giving one part for the kids, the other one for the senior's meeting. The seniors made the lights of the gym be turned on and also reduced the music volume. After their meeting ended, they ate all the refreshments of the dance and soon started dancing and made song requests.
- Diary of a Wimpy Kid: The Third Wheel (First and only appearance)