Is significantly different than the thesis question, How Many Protestants Were Killed in the Inquisition?
The answer to the thread's title is "not nearly enough." My answer to the second question is that I don't know of any who were.
(And, by the way, I wish that the Holy See would have never gotten rid of the Inquisition...we need it more now than ever)
Why the difference?
First, the Inquisition was not a period of time. The Inquisition was an office of the Holy See, established in approximately 1225 by Pope Gregory IX. Interestingly, he established it to reign in the actions taken by the civil ruler Frederick II, who was in the process of taking care of heretics in France on his own (mostly without any justice: in Frederick's France, if you were accused, you were guilty).
Secondly, as far as I could tell, the targets of the Inquisition were "Catholic". Catholics who embraced heretical doctrines. Its purpose was to root out those heretics and have them removed from the Church so they couldn't spread their rot further. As the Protestant's King James Version says:
[1Ti 6:20-21 KJV] 20 O Timothy, keep that which is committed to thy trust, avoiding profane [and] vain babblings, and oppositions of science falsely so called: 21 Which some professing have erred concerning the faith. Grace [be] with thee. Amen.
[Tit 3:10-11 KJV] 10 A man that is an heretick after the first and second admonition reject; 11 Knowing that he that is such is subverted, and sinneth, being condemned of himself.
Yes, I do wish the Inquisition existed today. There are so many people today who profess to be Catholic while professing the exact opposite, they need to be rooted out and expelled. Consider public political figures like the Kennedy clan, Pelosi, Biden, Kerry, and so on...and religious figures like Kasper, Bernardin, Wuerl, Mahony, etc., and their ilk. If the State where they live had a criminal penalty for heresy, so much the better.
Frederick II was Holy Roman Emperor, not King of France. The King of France as of 1225 was Louis VIII (reigned 1223-1226).
You sound like a murderous ISIS militant not a Christian.