The charity is very close to the the students' hearts because it cared for 15-year-old Francis - a former pupil at Finchley Catholic High School - who died in May this year after he was diagnosed with cancer.
Steve Nicolaou from Steve's Barber Shop in New Barnet visited the school and more than £6,650 pounds was raised.
Liam Hourican, pastoral leader for year 11 at Finchley Catholic High School, said: "Fundraising always has a large focus within the pastoral life at Finchley Catholic. This year it has even greater significance. Sadly, during the school closure towards the end of year 10, Francis lost his battle with cancer.
"His funeral cortege drove passed the school and a large number of members of the community were able to pay their respects to Francis and his family. When we returned in September, the year group decided that we are going to raise money for Noah's Ark Children's Hospice where Francis received so much care.
"The fundraising team proposed 'Brave the Shave' and we were fortunate enough to also get the support from Steve who kindly volunteered to visit the school and provide the 'new hairstyles' outside in the main playground with PPE and in a safe manner given the Covid-19 restrictions.
"The school raised money through JustGiving and traditional sponsorship forms and raised a total of £6,688.68. We are so thankful for everyone's generosity and support with our efforts. Theresa Villiers MP donated money as well as writing to congratulate us on our efforts and send her condolences also."
Anthony Hayman, Director of Fundraising and Communications at Noah's Ark, said: "A massive thank you to everyone at Finchley Catholic for this absolutely extraordinary fundraising effort. We can only care for children like Francis with the amazing support of the local community - and we're so grateful for all that you've done.
"I'm also delighted that you've chosen to raise it as part of our Moments that Matter campaign so that the figure will be doubled by generous backers to the charity on 22 / 23 November. That will mean your contribution to the babies and children who we support is more than £13k! Francis' sister has been instrumental in helping us create this campaign - it's wonderful that Francis' life has motivated so many people to support your local children's hospice".
To find out more about the Moments that Matter campaign that the students are involved with, click here