We make use of the unprecedented depth, spatial resolution, and field of
view of the Euclid Early Release Observations of the Perseus galaxy
cluster to detect and characterise the dwarf galaxy population in this
massive system. The Euclid high resolution VIS and combined VIS+NIR
colour images were visually inspected and dwarf galaxy candidates were
identified. Their morphologies, the presence of nuclei, and their
globular cluster (GC) richness were visually assessed, complementing an
automatic detection of the GC candidates. Structural and photometric
parameters, including Euclid filter colours, were extracted from
2-dimensional fitting. Based on this analysis, a total of 1100 dwarf
candidates were found across the image, with 638 appearing to be new
identifications. The majority (96%) are classified as dwarf ellipticals,
53% are nucleated, 26% are GC-rich, and 6% show disturbed morphologies.
A relatively high fraction of galaxies, 8%, are categorised as
ultra-diffuse galaxies. The majority of the dwarfs follow the expected
scaling relations. Globally, the GC specific frequency, S_N, of the
Perseus dwarfs is intermediate between those measured in the Virgo and
Coma clusters. While the dwarfs with the largest GC counts are found
throughout the Euclid field of view, those located around the east-west
strip, where most of the brightest cluster members are found, exhibit
larger S_N values, on average. The spatial distribution of the dwarfs,
GCs, and intracluster light show a main iso-density/isophotal centre
displaced to the west of the bright galaxy light distribution. The ERO
imaging of the Perseus cluster demonstrates the unique capability of
Euclid to concurrently detect and characterise large samples of dwarfs,
their nuclei, and their GC systems, allowing us to construct a detailed
picture of the formation and evolution of galaxies over a wide range of
mass scales and environments.