Leo

Leo (♌) is the 5th astrological sign of the Zodiac, originating from the constellation of Leo. In astrology, Leo is considered to be a "masculine", positive (extrovert) sign. It is also considered a fire sign and is one of four fixed signs. Leo is ruled by the Sun. Being the fifth sign of the zodiac, Leo has been associated with the astrological fifth house.

Individuals born when the Sun was in this sign are considered Leo individuals. The Sun is in Leo roughly from July 23 to August 22. Under the sidereal zodiac, it is currently there roughly from August 10 to September 15. The Sanskrit name of Leo in Hindu astrology is Siṃha.

Compatibilities
Based on Elements within the Zodiac, Leo is considered compatible with Aries, Sagittarius and Leo itself.
There are many variables that determine compatibility in astrology, such as birth dates, birth months, birth years, position of a sign within the Sun, the Moon, Stars. The signs listed as compatible with Leo do not reflect an individual profile or individual reading as interpreted within astrology, but rather reflect a general guideline and reference to compatibility as dictated by variables such as Qualities and Elements within the Zodiac. The branch of astrology dealing with interpersonal compatibilities is called Synastry.
Source : http://en.wikipedia.org/wiki/Leo