The most compatible sign for Aries is Sagittarius. But Leo could do well in a relationship with them, too, not only Sagittarius.
Leo male
aries
Gemmie
The Virgo woman is the most compatible sign for an Aries Male.
I would recommend Aries man for Sagittarius woman.
Sagittarius are excellently compatible with Aries, and can be good with Leo, too.
Aries
Aries is highly compatible with Gemini, Leo and Sagittarius. Aries is also highly compatible with other Aries and Virgo and they are partially compatible with Libra.
Libra,and sometimes Leo's if they're lucky.
Virgo
The easiest signs for Aries are the other fire signs. Leo, Sagittarius and Aries.
Any fire sign would be most compatible with Sagittarius. They include Aries and Leo.
AquariusAquarius, Leo, mostly Gemini, and Aries are compatible with Sagittarius. :)