Enzymatic hydrolysis of proteins produces bioactive peptides that have the potential to provide health benefits. This study examined the inflammatory- and immune-modulating properties of a flavourzyme-derived sunflower protein hydrolysate (SPH) and peptides. The SPH was fractionated into <1, 1-3, 3-5, and >5 kDa peptides by membrane ultrafiltration. The SPH blunted IL-1β stimulated NFκB activation and boosted IL-4/GM-CSF induced expression of surface markers CD14 and CD86, indicating maturation into a dendritic cell (DC) phenotype. Testing of SPH membrane ultrafiltration and HPLC fractions indicated that smaller and non-polar peptides were the most potent, respectively. Four novel peptides (YFVP, SGRDP, MVWGP and TGSYTEGWS) were identified and all of them blunted IL-1β stimulated NFκB activation. The peptides also boosted IL-4/GM-CSF induction of CD14, while only MVWGP and TGSYTEGWS boosted the expression of CD86. MVWGP was the most potent immune-modulatory peptide across all cellular assays, which was attributed to the presence of a methionine residue.