Like the title says, what were some famous or semi-famous volunteers that supported the Nationalist Spanish during the Spanish Civil War? I've always heard about the Republican volunteers, like George Orwell, Ernest Hemingway, and others, but I've honestly never heard of any who volunteered for the Nationalists.
Peter Kemp was an Englishman who fought as a volunteer with the Carlist Requetes, and later became an officer in the Spanish Foreign Legion. He wrote a memoir of his time with Franco's forces titled Mine Were of Trouble.
The most famous is probably Eoin O'Duffy, covered in this answer by /u/Georgy_K_Zhukov in our Spanish Civil War AMA. The Irish contingent for the Nationalists was small (~700 people) and saw little action, being sent home after a friendly fire incident.
The true "volunteer" status of various Condor Legion members is up for some debate. There is the infamous Oskar Dirlewanger, the aces Adolf Galland and Werner Mölders, and the Luftwaffe commander Hugo Sperrle. Another Condor Legion member was famous himself, as well as for his name. Wolfram von Richthofen was a cousin to Manfred and Lothar, served in the Spanish Civil War as well as in World War II.