This came after weeks of Houthi attacks on maritime shipping in the Red Sea and, days after U.S. and British naval forces shot down 21 Houthi drones and missiles, some of which President Joe Biden said directly targeted American ships.
Clips from U.S. Central Command showed American fighter jets taking off from an aircraft carrier at sea.
Meanwhile, the UK's defense ministry released video of what it said were jets launched from RAF Akrotiri on Cyprus.
Eyewitnesses filmed what appears to be strikes hitting the coastal Yemeni city of Hodeidah.
British defense officials say their attacks have hit the Houthis' ability to target ships.
While a U.S. official said over a dozen sites were hit with precision munitions.
While Washington says it has no intent to escalate tensions, the Houthis have vowed to retaliate - a Houthi spokesperson said after the strikes that they will continue targeting ships headed towards Israel.
The Iran-backed group has attacked 27 ships in the Red Sea since December.
They say it's a show of support for the Palestinians and Hamas.
The attacks have disrupted maritime shipping - some firms now avoid Red Sea routes, stoking up energy and food prices.
A U.S.-led task force called Operation Prosperity Guardian has been set up to defend shipping lines, and over 20 countries signed up to join it.
Thursday's strikes took place outside that coalition.
President Biden cautioned in a statement late on Thursday he would not hesitate to take further action if needed.
