Short answer
Yes. In the Hanafi school, and in the other three schools, it is not allowed for men to wear earrings or other piercings, because it copies women's adornment, and the Prophet ﷺ cursed men who imitate women. Eyebrow, lip and tongue piercings are not allowed for men either, and they are discouraged for women.
Piercing and earrings for men are makruh tahrimi as imitation of women. Parents should not pierce a boy's ears. A gold earring adds the further sin of a man wearing gold.
The four schools agree on this.
Explanation
The rule comes from the hadiths that curse men who imitate women and women who imitate men. Earrings have always been a women's adornment in Muslim societies, so the four schools agree that men may not wear them. That a style is common among men in some places today does not change this, since it is still copied from women's jewellery.
What is covered. Studs, hoops, clip-ons and magnetic earrings, in any metal. A gold earring is worse, because gold itself is haram for men: see is gold haram for men. Eyebrow, lip, tongue, nose and nipple piercings are also not allowed for men, both as imitation and as needless harm to the body.
If you already have a piercing. Take the jewellery out. You do not have to do anything to close the hole, and your wudu, ghusl and prayer are valid. If you got it before Islam, there is no sin on you for it.
For women. Ear and nose piercings are allowed, as explained in are nose piercings haram. Eyebrow, lip and tongue piercings are not normal women's adornment and are tied to rebellious fashions, so scholars advise against them.
The evidence
Sahih al-Bukhari 5885
Sahih... لعن رسول الله صلى الله عليه وسلم المتشبهين من الرجال بالنساء ...
"The Messenger of Allah cursed the men who imitate women and the women who imitate men."
Earrings for men imitate women's adornment.
Sunan Abi Dawud 4098
Graded sahih... لعن رسول الله صلى الله عليه وسلم الرجل يلبس لبسة المرأة ...
"The Messenger of Allah cursed the man who wears women's dress and the woman who wears men's dress."
Extends the rule to what is worn.
Where the ruling is recorded
- al-Durr al-Mukhtar with Radd al-Muhtar, Kitab al-Hazr wa al-Ibaha. Imitation of women by men and piercing boys' ears.
- al-Fatawa al-Hindiyya, Kitab al-Karahiyya, chapter on adornment, rings and jewellery. Adornment that is specific to women.
This answer is pending review by the scholars on our team. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.