Frank George Lenz (born 1867, probably died May 1894) was an American bicyclist and adventurer who disappeared somewhere near Erzurum, Ottoman Empire (now Turkey), in May 1894, during an attempt to circle the globe by bicycle.

He was hired by the magazine Outing (for which Stevens had worked) to publish reports and take photographs from his journey, and set out from the Smithfield Street Bridge in Pittsburgh on a Victory safety bicycle on May 15, 1892, with 800 onlookers wishing him well.

[5] Going first to Washington, D.C., and New York, Lenz traveled west across the United States and parts of Canada, reaching San Francisco on October 20.

Lenz found Teheran to be a delightful place and was loath to leave, but set out for Tabriz in April 1894, hoping to reach the Ottoman capital of Istanbul before the worst of the summer heat.

The Ottoman Empire was at this time going through a period of turmoil, with the killing of tens of thousands of Armenians taking place in the ongoing Hamidian Massacres.

It was difficult to ascertain what might have happened, but Alexander Terrell, the U.S. minister to the Ottoman Empire, felt sure that Lenz had been killed by Kurdish bandits.