A spokeswoman for the Great Western Hospital in the English city of Swindon said the singer was "much improved."
"Morrissey became unwell, and he was admitted overnight as a precautionary measure," she said on condition of anonymity, in line with hospital policy. "He's been seen by the medical team, much improved and now discharged home."
A note on the 50-year-old singer's Web site thanked fans for their good wishes.
Morrissey was performing at the Oasis Leisure Centre in Swindon, about 100 miles (160 kilometers) west of London, on Saturday night as part of his "Swords" tour when he was stricken. Two band members rushed to his side and dragged him offstage.
Fans were unsure what had happened. Jillian Moody told the BBC that some expected him to return to the stage.
"I didn't think he looked particularly well but then again, he's well known as a reclusive character so I sort of thought that was just the way he was when he was on stage," she said. "He kept putting his hand up to his mouth as if he felt sick or perhaps he was trying to hide something, but he didn't look particularly comfortable. He got through the whole song though ... to rapturous applause at the end."
He has rescheduled several shows this year, and is due to play a string of European dates through the rest of October and November.
Copyright © 2009 The Associated Press. All rights reserved.