Ontario Provincial Police said they were called to a home on Gamble Lane where they found the female victim on Monday evening.
The name of the victim has not yet been released.
A post-mortem examination is being scheduled to determine the cause of her death, though initial reports said the victim had been stabbed in the neck.
An OPP news release said only that officers had been called to the home to respond to a reported “family dispute.”
On Tuesday, a 36-year-old Rockwood man was arrested in Peel Region.
He is being transported back to Wellington County and will appear in a Guelph court on Wednesday to face a charge of first-degree murder.