Exemplary ultrasound probes with sub-aperture processing capable of dynamic focus are provided that generally include an array of transducer elements that form a sub-aperture in the ultrasound probe. The transducer elements can be assigned to dynamic delay update groups and an initial delay can be applied to ultrasound signals associated with the transducer elements of the sub-aperture. A sub-aperture processor can be configured to dynamically apply delay updates to the ultrasound signals associated with the transducer elements of the sub-aperture according to the dynamic delay update groups to which the transducer elements are assigned. Exemplary ultrasound systems with a dynamic focus and methods of transmitting ultrasound signals with a dynamic focus are also provided.