The majority of people in the World today with the surname Teskey are descended from just one family of four people that migrated as refugees from the German Pfalz (also known as the Southern Palatinate) to England and thence to Ireland in 1709. They were amongst many thousands of refugees who camped for a while at Blackheath on the outskirts of London. Several hundred families were transported to Ireland, many settling around Rathkeale in County Limerick. They became known as Irish Palatines. Their various German names became anglicised and our spelling soon became TESKEY. Their descendants spread to much of the English-speaking world in the 1800s and early 1900s. During the 1800s one branch of the family in Adare, Co Limerick, adopted the spelling TUSKEY. This variant has now spread around North America.

The name Teskey was also either adopted by or assigned to several families in Canada and USA who had migrated in the second half of the 19th and early 20th centuries from Germany and a number of eastern European countries. Their original name generally started with TESK but was either deemed too difficult by immigration officers or considered too Germanic at a time when it was not unusual to hide a German origin.