Diamantina is 290 km north of Belo Horizonte by road — about three and a half to four hours by car on the BR-040 and MG-010 highways. The drive is scenic once you enter the Serra do Espinhaço, though the road climbs steeply in the final stretch. Bus services connect Diamantina to Belo Horizonte several times daily; the terminal in Diamantina is a short taxi ride from the historic centre.
There is no commercial airport in Diamantina. Belo Horizonte's Confins airport (CNF) is the nearest arrival point for flights. Most visitors come by car or bus from BH; the combination of an overnight in Belo Horizonte and a morning departure gives you time to arrive by early afternoon.
Ouro Preto is about 130 km from Diamantina via BH, which makes a two-centre trip feasible if you have five or more days. The road between them passes through Belo Horizonte; there is no direct connection.