Pleurotus ostreatus (PO) and Hericium erinaceus (HE) have been traditionally used to treat various diseases, owing to their antioxidant, antimicrobial, neuroprotective, and antitumor effects. However, few studies have been reported on their antiaging effects. In this study, the antioxidant and antiaging activities of PO and HE aqueous extracts were investigated in ultraviolet A (UVA)-induced human dermal fibroblast cells (HDFs). The antioxidant properties of PO and HE aqueous extracts were measured by total polyphenol and ergothioneine content, and their antioxidant activity was analyzed with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical-scavenging assays. To demonstrate the antiaging effect of PO and HE aqueous extracts in UVA-induced HDFs, the secretion and mRNA expression of matrix metalloproteinase-1 (MMP-1), procollagen type I (PC1), and elastase were assessed by enzyme-linked immunosorbent assay (ELISA) and real-time PCR, respectively. The total polyphenol content in each extract was 13.6 and 11.7 mg gallic acid equivalents/g dry weight (DW), respectively, and the total ergothioneine content in each extract was 3.43 and 2.18 mg/g DW, respectively. The PO and HE extracts increased DPPH and ABTS radical-scavenging activity in a dose-dependent manner. In UVA-damaged HDFs, the extracts increased PC1 production but decreased MMP-1 production and elastase-1 activity. Furthermore, the mRNA levels of PC1, MMP-1, and elastase were recovered in the PO- and HE-treated UVA-irradiated HDFs compared to those in the irradiated control group. PO and HE aqueous extracts may be potentially used as a promising antiphotoaging agent.