The monarch stopped by the Sauchie Resource Centre during an unannounced visit before heading to The Gate Charity.
There, he spoke with members of the Wee County Veterans, a charity who work to provide support for those who served in the armed forces.
On his arrival, the king was greeted by the provost Donald Balsillie and Nikki Bridle on behalf of Clackmannanshire Council.
He also had the chance to meet Brian Leishman, Labour MP for Alloa and Grangemouth, during his visit.
Mr Leishman said: “It was a huge honour to welcome his majesty to Sauchie Resource Centre.
“He was very personable, spending time to speak to volunteers of the multi-award winning Sauchie Community Group along with members of Wee County Veterans as well as representatives from Cowden Japanese Garden and Clackmannanshire Council.
“Speaking to those who met the king on the day, I know it meant a great deal to everyone as it was a hugely memorable, once in a lifetime opportunity.
“Thanks go to the community for organising and turning out in numbers, officials for helping to welcome his majesty as well as the police and security teams for keeping everyone safe.”
Entering the Sauchie Resource Centre, King Charles met with and spoke to representatives from the Japanese Garden, Sauchie Community Group and the Wee County Vets.
The king spent a bit of time there, hearing from the volunteers on the work that they do, showing a keen interest in their volunteering.
Keith Turner, Sauchie Community Group president, said: “It was a great day. The sun shone over Sauchie to welcome his majesty King Charles III.
“We’re grateful to the Lord Lieutenant Johnny Stewart for arranging the visit with whom we’ve got a great relationship.
“It allowed us to showcase some of our invaluable and much appreciated volunteers. His majesty took time to speak to every indivdual there and had a tour of the centre and our wonderful community garden.
“It was also heart warming to see his majesty taking the time to talk to the well wishers and onlookers gathered outside.
“To be chosen to receive this visit is testament to the work everyone does and the difference we make to the community.
“The event really did show Sauchie at its best and we look forward to the year ahead.”
Lastly, the king spoke with eight members of the Wee County Vets, a group of former servicemen and women from across Clacks.
They provide support to ex-armed forces in helping them settle back into life while also giving them a platform to socialise with each other.
Jo Wilkinson, chair of the Wee County Vets, added: “He was charming, absolutely charming.
“He was very outgoing, very friendly and it was an absolutely wonderful day.
“We were very aware of the honour we had been given, he seemed very impressed with the work we were doing and very pleased by it.”