A simple search on Google for "Olé, Olé, Olé, football chant" or "olé spanish meaning" should lead you to this:
One evidence of the chant appeared in an article of the Spanish
newspaper La Vanguardia from 1982. It was during the final match of
the Spanish Football League that year. After Real Sociedad had been
proclaimed champion, the people at the Atotxa Stadium in San Sebastián
started to sing "Campeones, campeones, hobe, hobe, hobe", which
literally means "Champions, champions, we are the best". The latter
three words belonging to the Basque language. The chant expanded to
the rest of Spain, and become known as "Oé, Oé, Oé".
The word "olé" itself, being a Spanish interjection thought to be of
Arabic origin, or derived from the Germanic in the Iberian peninsula,
from which it also derives the English Hello and the neighbour
Portuguese Olá, mostly associated with the bullfighting of last
centuries, but also with the sports after the XIX century. It was
chanted when individuals seemed to rise above themselves in
performance.
The chant is used frequently in football games around the world, and
can be heard in Montreal Canadiens hockey games when the team is
winning. It is also used by supporters of the University of
California, Santa Barbara's Gaucho intercollegiate sports teams,
particularly the basketball and soccer programs, and led to the
creation of a mascot, simply named Olé.
It is also used by the supporters of the Republic of Ireland national
football team, especially in the song "Put 'Em Under Pressure".
In Argentina, sometimes the name of a person the people could be
cheering to is added at the end; e.g.: "Olé, olé olé ole, Die-go,
Die-go! (referring to Diego Armando Maradona).
Update
Here are some aclarations to make:
1. Its "Olé" and not "Oe" as some may claim
From the same wikipedia page:
Olé, Olé, Olé (The Name of the Game)
In 1987, Roland Verlooven produced a more popular version of the
chant, "Olé, Olé, Olé (The Name of the Game)". It was recorded by a
group known as "The Fans", and published by Hans Kusters Music. It
was released in Spain by Discos Games, and in Germany by ZYX Records.
The text of it goes "Olé, olé, olé, olé, we are the champions, we are
the champions", but there are widespread misunderstandings of it
rather being "...we are the champs, we are the champs" by many who
have simply not heard and understood the lyrics correctly.
Link to the original song: -> http://www.youtube.com/watch?v=L0GmxnlXv3s
2. Context of the chant
Top of the World (Olé, Olé, Olé)
"Top of the World (Olé, Olé, Olé)" is a stand alone single from
Chumbawamba. It was released in June 1998, and the single reached the
number 21 in the UK Singles Chart. It was also featured as the UK's
song on the World Cup 1998 compilation album Music of the World Cup:
Allez! Ola! Ole!. Their 1997 album Tubthumper was re-issued with this
song on the album.
3. Open ears!!!
Quote by comments on this question:
I'm Spanish and the people sing "oé" (NOT Olé) in many chants, for
example in this one: youtube.com/watch?v=VJvz9Hpx_ho or in this other
one: youtube.com/watch?v=NnXqD7_YnHU When they say Olé is just when
your team passes the ball many times and the opponent can't get it as
if it was a bullfight. – Javi
Well, the truth is that if you watch both videos using big speaker to amplify the sound you can hear clearly people using chanting Olé, Olé, Olé..., there is also some drunks as well as some others that don't know the full chant, and you can recognize them simply because their chant sounds more like "Oé, oé, Oé...."
That alone don't means that the chant is "Oé, oé, Oé...." or that there are two chants.
I know that for some, search in Google it's incredibly hard and confusing, so here is a direct link to the reference on wikipidia.
http://en.wikipedia.org/wiki/Olé,_Olé,_Olé
