In case the quotes from Aquinas seem too indirect, here is a far less quote from a respected authority, Bede the Venerable, from more than 500 years earlier:
The Earth is a sphere, set in the middle of the universe. It is not circular like a shield or spread out like a wheel, but looks round, like a ball.
This plaque with that quote has been on open display in the British Library:
Bede was a well known Benedictine Monk, teacher and scholar in 7th and 8th century Northumbria, known as "the father of English history" for writing Ecclesiastical History of the English People. He was very well known across Europe in his lifetime so it is unlikely that his view on the shape of the earth was unknown or aberrant for the time.