Measurement of the differential t$\bar{\mathrm t}$ production cross-section in 7 TeV proton-proton collisions in the single-lepton channel from ATLAS. The data comprise the full 2011 data sample corresponding to an integrated luminosity of $4.6\,\mathrm{fb}^{-1}$. The differential cross-sections are measured as a function of the jet multiplicity for up to eight jets using jet transverse momentum thresholds of 25, 40, 60, and 80 GeV, and as a function of jet transverse momentum up to the fifth leading jet. The results after background subtraction are corrected for all detector effects, within a kinematic range closely matched to the experimental acceptance.