On Friday they marched to 10 Downing Street - the Prime Minister's home.
There, they demanded their right to have 7 November declared National Gareth Day.
Wearing Gareth masks and t-shirts, they knocked on the Prime Minister's door and handed over a petition with 1,800 signatures.
If they get their way, this is what all Gareth fans will do on the day:
- At midday, fans will stop what they are doing to make Gareth-related sounds for one minute
- A star will be named after Gareth
- Indoor Gareth-themed street parties
- A Gareth lookalike competition
There's even a Gareth anthem especially for the event.
But so far, there's no news of a similar day to mark fellow Pop Idol Will Young...