The Hymenoptera constitutes one of the largest, and ecologically and economically most important, insect orders. During thepast decade, a number of hypotheses on the phylogenetic relationships among hymenopteran families and superfamilies have beenpresented, based on analyses of molecular and/or morphological data. Nevertheless, many questions still remain, particularly concerningrelationships within the hyperdiverse suborder Apocrita, but also when it comes to the evolutionary history of the ancestrallyherbivorous “sawfly” lineages that form the basal, paraphyletic grade Symphyta. Because a large part of the uncertaintyappears to stem from limited molecular and taxonomic sampling, we set out to investigate the phylogeny of Hymenoptera usingnine protein-coding genes, of which five are new to analyses of the order. In addition, we more than tripled the taxon coverageacross the symphytan grade, introducing representatives for many previously unsampled lineages. We recover a well supportedphylogenetic structure for these early herbivorous hymenopteran clades, with new information regarding the monophyly of Xyelidae,the placement of the superfamily Pamphilioidea as sister to Tenthredinoidea + Unicalcarida, as well as the interrelationshipsamong the tenthredinoid families Tenthredinidae, Cimbicidae, and Diprionidae. Based on the obtained phylogenies, and to preventparaphyly of Tenthredinidae, we propose erection of the tribe Heptamelini to family status (Heptamelidae). In particular, ourresults give new insights into subfamilial relationships within the Tenthredinidae and other species-rich sawfly families. Thee xpanded gene set provides a useful toolbox for future detailed analyses of symphytan subgroups, especially within the diversesuperfamily Tenthredinoidea.