Volubilis is itself a day-trip destination from Meknès or Fès, but the most natural pairing is with Moulay Idriss, just four kilometres away. The town is the burial place of Moulay Idriss I, the founder of the Idrisid dynasty and the man credited with bringing Islam to Morocco. Non-Muslims were once forbidden from staying overnight and the prohibition was only lifted in 2005; the town retains a quiet, sacred atmosphere that contrasts sharply with the bustle of Meknès. Walking the narrow streets up to the viewpoint over the two hills of the town takes less than an hour.
From Meknès it is also easy to reach the Middle Atlas mountain town of Ifrane, sometimes called the "Switzerland of Morocco" for its French colonial architecture and cedar forests. The drive takes about an hour and the town is a complete change of register from the imperial medinas of the north.
Fès is about 60 kilometres east of Volubilis and easily combined on a longer day if you have your own transport or hire a private driver from Meknès. The standard itinerary — Volubilis in the morning, Moulay Idriss for lunch, Fès medina in the afternoon — is ambitious but doable and gives a compressed tour through Roman, early Islamic, and medieval Moroccan history in a single day.