The Oscar winner appeared Saturday at the Texas Book Festival in Austin, where he was promoting his new book of short stories, "Uncommon Type: Some Stories."
Speaking to an audience of hundreds, according to the Associated Press, Hanks was answering audience questions when he said he was bored and had a question of his own.
That's when Hanks, 61, announced that Ryan McFarling had a question for Nikki Young, two people in the crowd. The actor said the question was, "Nikki, will you marry me?"
After McFarling and Young took the stage, the groom-to-be got down on one knee to complete the proposal. Young said yes!
Hanks is well-known for acts of kindness towards the fellow man. Earlier this year, he surprised the White House press corps with a new espresso machine.
And in 2015, he found and returned a Fordham University student's lost ID card.
Hanks has also helped a Girl Scout troop in San Francisco sell their famous cookies, buying four boxes and even leaving a $20 tip, according to the Los Altos Town Crier.