Except for the Danube in the south, the city is surrounded by forests and hills which rise to altitudes of over , some of them part of the Swabian Alb.
Nasproti starega mestnega jedra, na drugi strani reke, leži pobrateno mesto Neu-Ulm v zvezni deželi Bavarski, ki je manjše od Ulma in je bilo do leta 1810 del njega (populacija ~ 50.000).