A fundraiser for an Irish charity that supports children struggling with grief and loss has been set up in memory of the young soldier.
The Donegal native was shot dead last month when the vehicle he was driving came under fire near Beirut.
Comrades have now launched a GoFundMe in his memory, raising money for an Irish charity that supports children struggling with grief and loss.
The fundraiser has already knocked the original target of €1,000 out of the park.
It has hit almost €10k in just three days.
"Do you want to join the lads from 121 UNIFIL in Lebanon in making a difference?” says organiser Alex Tate.
"We are raising money in aid of Rainbows Ireland Child & Youth Grief & Loss Support CLG and every donation will help.
"Thank you in advance for your contribution to this cause that means so much to me.”
The crew are set to run 100km during the month of January to help the charity in Seán’s memory.
Donors to the cause have celebrated organisers for their efforts.
A poignant note of support from Olga and John Rooney – members of the young soldier’s family – reads: “Love you Seán my wee brother.”
Others celebrate the “wonderful and worthy cause” with messages of support.
The heart breaking funeral of Private Rooney was a deeply emotional affair in the days before Christmas.
“He was placed in my arms when I was 16 years old, and he gave me purpose,” his mother Natasha said.
"I wanted to do better for Seán. I wanted to finish school for Seán. I wanted to go on the third level education for Seán, to buy my house for Seán. I wanted Seán to have a mother he could be proud of.
“In his life he gave me purpose, and in his death I will find new purpose.”
Spontaneous applause erupted during the service as the grieving mum described her son as a “national hero.”
"He was the most beautiful baby, the most gorgeous wee boy, and the most handsome man you will ever meet, but that is a fraction of what was on the inside.
"I will love you forever son, and I cannot wait to be reunited with you in heaven,” he said through her tears while the mourners clapped.
The GoFundMe in aid of of Rainbows Ireland Child & Youth Gried & Loss Support can be found here.