Irish moss

Irish moss may refer to:
 * Chondrus crispus, a commonly gathered seaweed; a clarifying agent in beer brewing
 * Mastocarpus stellatus, a less commonly gathered seaweed
 * Sagina subulata, a terrestrial plant with needle-like leaves
 * Soleirolia soleirolii, a terrestrial plant with round leaves
 * Arenaria verna, a terrestrial plant in the genus Arenaria
 * Gracilaria, a genus of seaweed
 * Irish moss (drink), a beverage in Jamaican cuisine made from Gracilaria
 * Gelidium amansii, a genus of seaweed which yields Agar Agar