Seawater, sea sand and coral aggregates are emerging as the viable alternatives to freshwater, natural fine and coarse aggregates, respectively in offshore construction projects. This study firstly investigates the material property of seawater sea-sand coral aggregate concrete (SSCAC). To enhance SSCAC performance and reduce carbon dioxide emissions, various minerals, including fly ash (FA) and limestone powder (LSP), were used to partially replace ordinary portland cement (OPC). Given SSCAC’s higher chloride ion content, fiber-reinforced polymer (FRP) was employed for confinement instead of traditional steel due to its better corrosion resistance. Experimental and analytical studies were conducted on the stress-strain relationship of FRP-confined SSCAC. A total of eight concrete column specimens, including three unconfined and five FRP-confined columns, were tested under uni-axial compression. The major testing parameters were FRP thickness and the replacement ratio of FA or LSP. Results indicated that the stress-strain behavior of FRP-confined SSCAC differed from that of FRP-confined normal concrete.