The sanctions targeted 16 entities and individuals across the Horn of Africa region, the United Arab Emirates, and Cyprus, the Treasury said in a statement.
The action, which follows US sanctions against a separate network linked to al Shabaab in October 2022, freezes any US assets of those targeted and generally bars Americans from dealing with them.
It said Al Shabaab, which Washington considers a terrorist group, generates over $100 million a year, including by extorting local businesses.
Al Shabaab, linked to Al Qaeda, has been waging an insurgency against the Somali government since 2006 in a bid to establish its own rule based on a strict interpretation of Islamic Sharia law.
“The threat posed by al-Shabaab is not limited to Somalia,” State Department spokesperson Matthew Miller said in a statement.
“Al-Shabaab’s revenues are disbursed to other al-Qa’ida-linked groups worldwide and help fund al-Qa’ida’s global ambitions to commit acts of terrorism and undermine good governance.”