The bloc was the largest in parliament before its lawmakers resigned in protest at the crushing of 2011 protests for an elected government and Washington has called the crackdown on it "alarming".
The administrative court had not been due to meet on the government's request to dissolve it until October 6 but brought the session forward at the request of Justice Minister Sheikh Khaled bin Ali Al-Khalifa, a judicial source said.
The court already suspended all of Al-Wefaq's activities on June 14, ordering its offices closed and assets frozen.
The justice ministry said the bloc provided a haven for "terrorism, radicalisation and violence" and opened the way for "foreign interference" in the kingdom's affairs.
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That was an allusion to Shiite Iran, which Sunni-ruled Bahrain accuses of fomenting unrest among its Shiite majority.
Despite repeated appeals from its US ally for "reform and reconciliation", Bahrain has carried out an intensifying crackdown on leading Shiite figures in recent weeks.
On Monday, it stripped the kingdom's top Shiite cleric Sheikh Isa Qassim of his nationality, prompting street protests in his home village of Diraz, west of Manama.
Tiny but strategic Bahrain lies just across the Gulf from Iran and is the home base of the US Fifth Fleet.
It has been wracked by persistent unrest ever since the crushing of the 2011 protests.