Bill Mountjoy

{{Short description|Canadian baseball player (1858–1894)}}

{{Use mdy dates|date=July 2024}}

{{Infobox baseball biography

|name=Bill Mountjoy

|position=Pitcher

|image=

|bats=Left

|throws=Right

|birth_date={{birth date|1858|12|11|mf=y}}

|birth_place=London, Canada West

|death_date={{death date and age|1894|5|19|1858|12|11}}

|death_place=London, Ontario, Canada

|debutleague = MLB

|debutdate=September 29

|debutyear=1883

|debutteam=Cincinnati Red Stockings

|finalleague = MLB

|finaldate=August 18

|finalyear=1885

|finalteam=Baltimore Orioles

|statleague = MLB

|stat1label=Win–loss record

|stat1value=31–24

|stat2label=Strikeouts

|stat2value=164

|stat3label=Earned run average

|stat3value=3.25

|teams=

• Cincinnati Red Stockings (1883–1885)
• Baltimore Orioles (1885)

}}

William Henry Mountjoy (a.k.a. Medicine Bill) (December 11, 1858 – May 19, 1894) was a Canadian-born pitcher in Major League Baseball.