"Holy Toledo!" is an exclamation of surprise used in American and Canadian English. It is widely believed to have stemmed from the common presence of TOLEDO Scales found throughout retail stores and sidewalk displays after the turn of the 19th Century. Shoppers and onlookers would use the expression to voice their dismay when they saw how much something (or someone) weighed.
The TOLEDO Scale Corporation was the largest U.S. manufacturer of industrial and retail scales. Its founder, Henry Theobald, had launched an innovative store scale with an automatic weight and price display in 1901, and through continued innovation, TOLEDO established its leadership thereafter as a standard in the weights & measurements business.
TOLEDO scales can still be commonly found in your local grocery where you use them to weigh fresh produce. They have a large dial display (like a clock face) and a hanging basket. In the past their larger companion models were commonly found as a novelty item on sidewalk displays on which you could stand on the scale, drop a coin and receive your weight stamped on a card accompanied with a token fortune, etc. Onlookers and passersby would sometimes gawk when perhaps an overweight person would use the scale and their weight was displayed on the large dial for all to see and exclaim "Holy Toledo!"
