The sport of football in the country of Bahrain is run by the Bahrain Football Association, and it is the most popular sport activity in the country.
Bahrain has its own top-tier domestic professional football league, the Bahraini Premier League
. It features 10 football clubs that play a two round robin set , with each team playing a total of 18 fixtures. The winners of the domestic championship qualify for the AFC Cup.
The league uses a promotion and relegation system with the Bahraini Classification League, Bahrain's second tier football league. The season usually starts in September and concludes in May, as in other football leagues. The first season was held in 1952. Although games are played on a home and away basis, almost all games are played at the Bahrain National Stadium.
The bottom placed club is relegated with the team finishing second bottom entering a relegation/promotion playoff match. The most successful club in the league's history is Al-Muharraq SC. The current reigning champion of the 2011-2012 football season is Riffa club.Top Football clubs in BahrainAl-Muharraq Sports Club
Al-Muharraq Sports Club (Arabic: نادي المحرق الرياضي) is a Bahraini football club based in Muharraq. It is the oldest sports club in the Gulf region. Al-Muharraq Sports Club has won the Bahraini Football Premier League 31 times. Al-Muharraq Sports Club also takes part in other sports than football like Basketball and Volleyball. Historically, Al-Muharraq Sports Club football team resembles most of Bahrain national football team.
More info: http://en.wikipedia.org/wiki/Muharraq_ClubBahrain Riffa Club (includes West Riffa)
Al-Riffa Sports Club (Arabic: نادي الرفاع الرياضي) is a Bahraini football club based in Riffa, playing in the top division of Bahraini football league. The club was founded in 1953 by the Kingdom's Prime Minister, Prince Khalifa bin Salman Al Khalifa.
More info: http://en.wikipedia.org/wiki/Bahrain_Riffa_ClubAl-Bahrain Sports Club
Al-Bahrain Sports Club (Arabic: نادي البحرين الرياضي), otherwise simply known as Bahrain, is primarily a Bahraini football club based in the island-governorate of Al-Muharraq. Their football team currently plays in the Bahraini Premier League. Their home football stadium is the Al Muharraq Stadium, which they share along with their local island rivals, Al-Muharraq Sports Club. Bahrain Club also have teams for other sports, such as Basketball, Team Handball and Volleyball.
More info:http://en.wikipedia.org/wiki/Bahrain_ClubAl-Ahli Club of Manama
Al-Ahli Club of Manama (Arabic: النادي الأهلي البحريني) is a Bahraini sports club based in the capital city of Manama. They used to play in the top division in Bahraini football but were relegated to the second division after finishing ninth in the 2011-2012 First Division league. The club also fields players in other sports such as basketball, handball, and volleyball. Their home stadium is Al Ahli Stadium, although like all other teams in Bahrain they mainly play on Bahrain National Stadium.
Al Ahli (formerly known as Al Nusoor), along with Muharraq Club, are considered to be the pillars of sports in Bahrain. The matches between Al Ahli and Muharraq are known to draw the largest fan attendance in the Bahraini league and is considered to be the Bahrain Derby. 
Today they still are known to have the best youth products on their side, and still focus primarily on the youth players to challenge for the league title. Amongst the players that Al Ahli have produced recently are A'ala Hubail (the Asian Cup 2004 top scorer), Ali Saeed, Mohammed Hubail, and Mohammed Husain. The current president is Fuad Kanoo and the vice president is Moanes al Mardi.
East Riffa Club
You can find more info about football in Bahrain here: http://en.wikipedia.org/wiki/Football_in_Bahrain