Now, the campaign has joined forces with Sport Relief to encourage even more women and girls to "get active, raise cash and change lives".
Some of our favourite 'This Girl Can' mantras have been adapted for Sport Relief and will appear in new short films giving women ideas on how to get involved.
The film featured above is based on the mantra "every red face counts", and features Lara, from Newbury.
At school Lara, now 23, was put off P.E. by her lack of co-ordination and felt intimidated by other girls who she believed were naturally much better than her. This only got worse once she hit puberty.
Then she discovered running. Even though at first she could barely run a mile, Lara's confidence began to improve. She loved the fact that it wasn’t competitive and the only person pushing her was herself.
A friend then introduced her to rowing and then to climbing, which she got more involved in while she was at university thanks to the facilities.
She’s now even started to take part in competitions and has been surprised by how supportive everyone is.
"I love being involved in This Girl Can. Even though I’m bright red and a bit sweaty in my film, I don’t mind as I think it’s really important to show images that other women can relate to," she said.
"It’s great to think that by being part of the campaign, I might have inspired someone to get active."
Lara's mum will be trying to swim 100 lengths for Sport Relief and Lara will be running for how ever long this takes her mum to complete the challenge.
If, like a younger Lara, you think sport isn't for you, why not use the Sport Relief initiative to try out something new?
There are lots of different ways you can get involved, from signing up to an event at the Sainsbury's Sport Relief Games to organising a sponsored netball match.
Comedienne Jo Brand and F1 presenter Suzi Perry are among those backing the 'This Girl Can' campaign.
Thousands of women have already created their own 'This Girl Can' posters using the campaign’s mobile web app. This has also been adapted so that women raising money can show everyone what they’re doing.
Tanya Joseph, 'This Girl Can' campaign director, said: "Fundraising is a lot like exercise – it’s not about what you do or how you do it. What matters is that you’re doing something that’s good for yourself, and good for other people.
"Women come in all shapes and sizes and levels of ability, and they should all feel able to exercise and play sport, and to do it for great causes like Sport Relief."