Paddon was educated at Woodbridge Grammar School, and Repton School under William Mordaunt Furneaux. He entered University College, Oxford in 1900; his grandfather James Van Sommer died in 1901. A troubled student, he graduated in 1906. Through the Fishermen's Mission (RNMDSF), he encountered again Wilfred Grenfell, who had visited Repton. He studied at St Thomas's Hospital, qualifying in early 1911, and taking a position at the Guest Hospital in the Midlands.
