partial / older only. An English translation exists but is partial or older than the critical edition. The gap is a modern, complete translation from the original. A rendering of a daughter version does not count here: it is recorded on the dossier of the text it actually translates.
Why this is in the register
No dedicated English edition. The Greek fragments (Eusebius, HE 2.23; 3.20; 4.22) are rendered inside ANL vol. 22, 'Fragments of the Second and Third Centuries' (Edinburgh: T. & T. Clark, 1871), section 'Hegesippus', and inside translations of Eusebius (Loeb, Lake/Oulton 1926-32; NPNF II.1): https://archive.org/details/AnteNiceneChristianLibraryV22. Later-discovered fragments were published only in German (Neue Fragmente des Papias, Hegesippus und Pierius, Leipzig 1888) and have not been Englished; HOLLIS Primo 'Hegesippus' returns that German volume, Brill dictionary entries, and the Cambridge article 'The Hypomnemata of Hegesippus' (a study, not a translation): https://hollis.harvard.edu/discovery/search?query=any,contains,Hegesippus&tab=Everything&search_scope=MyInst_and_CI&vid=01HVD_INST:HVD2&offset=0 No volume for this text was located in ANF, NPNF, Fathers of the Church, Ancient Christian Writers or Popular Patristics.
Fragments are quoted by Eusebius; the F1K Eusebius Historia Ecclesiastica (Dindorf 1871, Teubner) carries the Greek of the quotations. Routh, Reliquiae Sacrae vol. 1 (Oxford 1846), prints the Greek fragments with Latin notes (the scan contains the 'HEGESIPPUS' section). The 1871 ANL translation covers the fragments known in 1871 only; the 1888 additions exist in German only.
Lawlor, Hugh Jackson, 1860-1938. "Evsebiana essays on the Ecclesiastical history of Eusebius, Bishop of Caesarea." Oxford : Clarendon Press, 1912. https://hollis.harvard.edu/permalink/f/1s5nto6/990022359170203941