Walter Henry Porter (June 1858 – December 30, 1906) was an American Major League Baseball player born in Vergennes, Vermont who pitched for three teams during his six-year career.

Porter began his career in the short-lived Union Association for the replacement team Milwaukee Brewers.

It was for this team that he struck out 18 batters in one game on October 3, 1884.

[1] When the Association folded following the season, he was picked up by the Brooklyn Grays, with whom he was their star pitcher.

[2] After having a 15–24 record in 1887, Porter was purchased by the Kansas City Cowboys for 1888.