Oliver is a classic (Shakespeare and Dickens) and has recently become popular in Sweden.
Leonardo is also Shakespeare but seems more demanding, I expect an Italian or a Spanish surname (like DiCaprio :)
But I do like just
Leo.
"You sought a flower and found a fruit. You sought a spring and found a sea. You sought a woman and found a soul. You are disappointed."
"It does not become me to make myself smaller than I am." (
Edith Södergran 1891-1923)