Police Scotland confirmed that 24-year-old Daniel Hussain, who absconded from the prison near Dundee on 13 July, had been apprehended.
Kieran Kiely, 23, who went missing from the open prison at the same time, was traced on Monday.
Police had warned the public not to approach either men during their initial appeal for information.
The second of two inmates who absconded from Castle Huntly open prison has been traced.