The Queen has been greeted by school children and members of the public during a tour of the Royal British Legion Industries (RBLI) village.
The village in Aylesford, Kent, provides housing, welfare support and care to more than 300 people with connections to the Armed Forces.
The Queen opened the new Appleton Lodge care facility and visited the Centenary Village housing project.
She also placed soil into a hole containing a time capsule.
The capsule commemorates the Queen's visit, and is not to be opened for 100 years.
She enclosed a letter in the capsule saying: "I wish to congratulate RBLI on their centenary, and their support of veterans over the past 100 years.
"Today is a moment of celebration, but also a time of reflection on the sacrifices the Armed Forces make in times of need.
"I send my warmest best wishes to RBLI and all who support them."
During her visit, ahead of Remembrance Day, the Queen met village residents, including 99-year-old World War II veteran John Riggs.
He is the first resident of Appleton Lodge after living in the RBLI's existing accommodation in Aylesford for more than 50 years.
Mr Riggs served in the Middle East and was behind enemy lines in Burma.
He was part of the Chindits, a special operations unit formed to fight behind enemy lines to protect India from Japanese invasion.
Meeting the Queen in his room, he reminded her that he is turning 100 in 2020.
Smiling, she replied: "I must remember to get your card on the right date next year."
RBLI, which was formed in 1919, launched a campaign in 2019 to build the Centenary Village, which the charity says will see it support hundreds of the most in-need ex-servicemen and women every year for another century.