Day entered municipal politics in the 1930s, first as an alderman[2] and then as a controller before being elected mayor in 1938 and serving until 1940.

Italian-Canadian men were interned by the federal government shortly after Italy declared war on Canada during World War II; Day announced on June 11, 1940, that their families, despite now lacking a breadwinner, would be denied welfare.

"Heritage Funeral Centre, "Ralph Day Chapel" is in Toronto on Overlea Boulevard.

In 1949 Day won the equivalent of $100,000 (Canadian) on an Irish Sweepstakes ticket on the horse Russian Hill.

Seriously ill at the time with "a blood complaint" resulting from an infected tooth, he described the news as "the best tonic in the world".