Traffic was stopped in both directions on the M5 near Junction 5 for Droitwich Spa after the brown horse was seen wondering along the hard shoulder at around 8.30am on Tuesday.
The horse was calmed and led to safety by three men in high-visibility jackets while onlookers took photos of the scene.
The motorway was eventually reopened at around 10.15am after a horsebox arrived to collect the animal, while congested traffic cleared during the day.
A spokeswoman for West Mercia Police said: "Police were called shortly after 8.30am this morning following report of a horse loose on the southbound carriageway of the M5 between junction 5 for Droitwich and 6 for Worcester.
"Officers worked with colleagues from National Highways to close the road while the horse was secured and safely transported off the motorway, where it was later reunited with its owner."