Make text into a link in OmniGraffle
Linking to a box or other drawing object is the easy thing to do. It's not a true link to text like you asked, but maybe a small object surrounding the text would be worth the hassle.

Now on to the easy option:


Select any object / shape that exists in the canvas/layers picker (or is visibly selectable).
Select the inspector control if the right inspector pane is not visible (click on the circle with an i in it)
Select Properties (the blue gear below)



* Open the action triangle (if needed) and select @ Open a URL and paste in the link you wish to have linked

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