Sussex Police have confirmed the 25-year-old man had gone to help the youngsters, who were in a rubber ring, when he lost his life.
He managed to get both children to safety at the busy beach at 11am on Saturday.
A Sussex Police spokesman said: “On Saturday a tragic incident occurred on West Wittering Beach.
“A 25-year-old male accidentally drowned.
“He had gone to the assistance of two children playing in a rubber ring. He managed to get them to safety but it sadly resulted in him drowning.”
For full details of the tragedy, see this week’s Chichester Observer.