One of the first of the appealing Irish surnames to take off in this country, Donovan has long outgrown its "Mellow Yellow" association, which came via the single from a sixties singer-songwriter named Donovan.
Donovan was Scottish-born Donovan Leitch, whose name was probably inspired by his father Donald's. He proved to be an adventurous, celestial namer himself--three of his children are Astrella Celeste, Oriole Nebula and Ione Skye.
Another potential namesake is Minnesota Vikings quarterback Donovan McNabb.
Donovan was in the USA Top 1000 as early as 1900, now ranking at Number 282.
Related options are surname Donegan and place name Donegal.