Sheikh `Abd Allah b. Bayyah, professor at `Abd al-`Azîz University in Jeddah
It is permissible for you to sit for jury duty if this would be of help to people who have been wronged or would secure their rights. It does not matter if those people are Muslims or non-Muslims. Such an activity is worthy of reward.
However, this ruling is conditional on your not issuing any unjust verdict against someone on account of the applicable laws.
If you will not be able to reach a verdict that is just, then you may not sit for jury duty, since you would be ruling by falsehood which is something that you are commanded by Allah to reject. Allah says: “Whoever rejects falsehood and believes in Allah hath grasped the most trustworthy hand-hold that never breaks.” [Sûrah al-Baqarah: 256]
Allah also says: “Have you not turned your thoughts to those who declare that they belive in the revelations that have come to you and to those before you? Their (real) wish is to resort together for judgment (in their disputes) to falsehood though they were ordered to reject it. But Satan’s wish is to lead them astray far away (from the right).” [Sûrah al-Nisâ’: 60]
Since the jury is a supreme judicial body, the jurors participating on it will be in a position of power to bring justice to people who have been wronged.
And Allah knows best.
Source: Islam Today