Hashem Abedi is the brother of Salman Abedi, who set off a bomb at the end of an Ariana Grande concert on May 22, killing 22 people and wounding hundreds.
Salman Abedi blew himself up in the attack.
Police say the warrant for Hashem Abedi relates to the murder of 22 people and the attempted murder of others.
Investigators have said they didn't believe there was a large group involved in the attack but that they believed others were involved in the planning. They named Hashem Abedi as a suspect.
The warrant for his arrest was issued by a Westminster Magistrates' Court judge and approved by the home secretary.
