This poster presents the latest results on searches for pair production of supersymmetric partners of the top and bottom quarks using the LHC proton-proton collision data, recorded by the ATLAS detector at a centre of mass energy of $\sqrt{s} = 13$ TeV from 2015 to 2018, corresponding to an integrated luminosity of 139 fb$^{-1}$. Three main analyses are presented; a search for top squark pair production in events with $Z$ bosons, a search for bottom squark pair production in events with two Higgs bosons and a search for top squark pair production in events with a three body decay. The ATLAS Collaboration has also published new results which offer interpretations with third generation squarks and extend the current exclusion limits.