  We estimate here the age of one of the prototypes of the Beta Pic-like stars,
Fomalhaut, based on the properties of its common proper motion companion Gl879.
By combining constraints derived from the lithium abundance, rotational
velocity, HR diagram position, and coronal activity we conclude that the age
for Gl879, and hence the age for Fomalhaut, is 200$\pm$100 Myr. This age
estimate agrees quite well with the completely independent age estimate derived
directly from isochrone--fitting to Fomalhaut's position in an HR diagram, and
thus confirms that circumstellar dust disks can persist in A stars for several
hundred Myr.
