He was portrayed by Oliver Ford Davies.
Like his son, he was very arrogant at the beginning, but much more reasonable. His son wanted to layoff/fire employees in order to save money, but then Christopher Robin arrived to tell him and his son of his new and quickly improvised plan to reduce luggage prices, to sell them to regular people and give employees paid leave, to which he agreed. His son didn't and thought that Robin he lost his marbles. Winslow Sr. shushed his son and was mad at him for disturbing his and Christopher's conversation. His son is then humiliated when Robin reveals that Jr. didn't contribute to the plan and had been playing golf all weekend. At the end, when Eeyore stared at Winslow Jr., he saw that and told that to his father, prompting Winslow Sr. to say that Jr. was the one who lost his marbles, not Christopher.