William Walsingham Jr. was an American Major League Baseball executive who spent the majority of his thirty-year career with the St. Louis Cardinals. He began his tenure with the franchise as a ticket-taker under the ownership of his uncle, Sam Breadon. Over the years, Walsingham rose through the ranks, eventually becoming a vice president of the club by the early 1940s. Following the departure of long-time general manager Branch Rickey in 1942, Walsingham assumed the role of chief of baseball operations, effectively serving as the general manager without the formal title.
When Breadon sold the Cardinals in 1947, Walsingham remained with the organization as a vice president and board member. In 1953, following the forced sale of the team by owner Fred Saigh, Walsingham briefly stepped in as the team's official National League representative and chief executive. He continued to serve under the new ownership of August A. Busch Jr. until resigning in October 1955, citing a belief that a baseball club could not be successfully run by two people with conflicting authority.
In 1957, Walsingham joined the Baltimore Orioles as an executive vice president, a role intended to oversee and curb the spending of general manager and field manager Paul Richards. However, Walsingham struggled to establish authority within the Orioles organization and was dismissed in late 1958. He subsequently returned to St. Louis to work as a marketing consultant for Anheuser-Busch. He passed away from a heart ailment in 1969 at the age of 59.
