Records of taxa of benthic marine macroalgae in the Philippines continue to increase as molecular-based biodiversity and systematics research involving seaweed specimens collected from various localities in the country continue to grow. Several molecular systematics studies on seaweeds within the last decade also resulted in taxonomic, nomenclatural, and classification changes, consequently affecting our knowledge and understanding of the biodiversity of the Philippine seaweed flora. Moreover, global efforts to make biodiversity resources that are deposited in various herbaria openly available through online databases provide a good opportunity to reassess our current foundational biodiversity knowledge on these ecologically and economically important marine resources. Herein, we provide an updated checklist of Philippine seaweeds by integrating results of recent biodiversity and systematics studies and by perusing open-access records of seaweeds collected from the Philippines that are deposited in foreign herbaria and/or found in online databases. We report a total of 1,065 seaweed taxa in the Philippines; this is composed primarily of 600 red seaweed taxa (Florideophyceae and Bangiophyceae, Rhodophyta), followed by 272 green seaweed taxa (Ulvophyceae, Chlorophyta), and by 193 brown seaweed taxa (Phaeophyceae, Ochrophyta). We added a total of 104 new records (including recently described species) to the latest checklist on Philippine seaweeds in 2013, more than half of which were derived from records of the collections deposited in foreign herbaria. The latter highlights the need to make herbarium collection records accessible and underscores the important role of herbaria (and museums in general) in documenting and preserving biodiversity resources of biodiversity hotspot areas such as the Philippines. We also reiterate here the call to increase support in building local expertise and funding on marine (seaweed) biodiversity and systematics research as these are crucial not only in documenting and conserving our marine biodiversity resources but also in developing them for their socio-economic values.