Tim Ahearne (Timothy Joseph Ahearne; August 18, 1885 – December 1968) was an Irish athlete who competed for the United Kingdom of Great Britain and Ireland in the 1908 Summer Olympics.
He was born in Dirreen, Athea and died in Athea, Limerick and was the older brother of Dan Ahearn.
Ahearne won the gold medal in the triple jump at the 1908 Summer Olympics held in London, while representing Great Britain and Ireland (as Ireland was not recognised separately at the time by the International Olympic Committee).
In the long jump competition he finished eight. He also participated in the standing long jump event but his result is unknown. In the 110 metre hurdles competition he was eliminated in the semi-finals.
After his Olympic victory in 1908, Ahearne emigrated to New York in 1909, and joined the Irish American Athletic Club. He also competed for time for the rival New York Athletic Club.