The present disclosure is directed to providing a gas-containing solution production method and a gas-containing solution production system for effectively using a gas and producing a gas-containing solution with high efficiency. According to the present disclosure, a gas-containing solution production method includes an atomization step of atomizing a liquid stored in a first container, a generation step of generating, by bringing a gas into contact with the atomized liquid, droplets with the gas dissolved, a transfer step of transferring the gas-dissolved droplets into a second container via a first flow path, separating the gas-dissolved droplets, and transferring a residual gas into the first container via a second flow path, and a collection step of collecting the separated gas-dissolved droplets.