Hopkins was born in Chester, Connecticut. His major league debut came on the same day that Babe Ruth hit his record-tying 59th home run on September 29, 1927. Hopkins said he did not know that he would be facing Ruth when he entered the game in the fifth inning with the bases loaded. He finished his career with a record of 1-1, 11 strikeouts, and a 2.96 earned run average in 11 games; he left St. Louis following the 1929 season after injuring a tendon.
Hopkins died in Deep River, Connecticut at 99 years of age. At the time of his death, he was reported to be the oldest living former major-league player.
"Then he (Babe Ruth) strolled out from the Yankee bench and walked up to the plate. I was not excited or awed." - Paul Hopkins in The Hartford Courant (1998).