We investigate electronic excitations in GaAs–AlGaAs quantum dots by means of resonant inelastic light scattering in the presence of an external magnetic field B. At magnetic field B=0, we observe a series of discrete electronic excitations, namely, charge-density excitations (CDEi) and spin-density excitations (SDEi), in one and the same quantum dot sample. We find at finite magnetic field, additionally to the well-known splitting of the CDEi modes (plasmons), a quite similar splitting of the lowest SDE mode whose energy is very close to the single-particle level spacing in the quantum dot. In analogy to the edge magnetoplasmon, we call this excitation an edge spin-density mode.