Short answer
Yes. Dating and girlfriend or boyfriend relationships are haram in the Hanafi school and all four schools. The Quran rules out taking secret lovers, and Islam closes the doors to zina: being alone together, flirting and touching. Working or studying alongside the opposite sex with modesty is allowed. If you like someone, involve your families and seek marriage.
A romantic relationship outside nikah is haram, as are seclusion (khalwa) with a non-mahram, touching, flirtatious talk and lustful looking. Necessary and modest interaction at work, school or in trade is permitted.
The four schools agree on this.
Explanation
When the Quran describes lawful marriage, it describes chaste men and women who do not take 'secret lovers'. That phrase describes the modern girlfriend or boyfriend exactly. Allah also says do not even approach zina, so Islam forbids the steps that lead to it, not only the act. The four schools agree on this.
The Prophet ﷺ said that no man is alone with a woman except that Shaytan is the third with them, and he forbade a man to be alone with a non-mahram woman. He also said that the eyes and the tongue can commit zina in their own way, by looking and by talk. So private chats, late-night calls and DMs of a romantic kind fall under the same ruling as meeting in person.
What about friendship? Close, casual friendship between a man and a non-mahram woman is not permitted in the Hanafi school, because it so easily becomes something more. You can still:
- work and study with classmates and colleagues of the opposite sex, politely and professionally;
- talk in groups about tasks, lessons and business;
- help someone in need.
Having feelings for someone is not a sin. Acting on them in haram ways is. If you are drawn to someone, take the halal route: tell your parents or the woman's wali, meet with family present, pray istikhara and move towards nikah. If you are already in a relationship, repent, and either end it or turn it into a marriage quickly. Allah forgives those who turn back to Him.
The evidence
Quran, Surah Al-Maaida 5:5
ٱلْيَوْمَ أُحِلَّ لَكُمُ ٱلطَّيِّبَٰتُ ۖ وَطَعَامُ ٱلَّذِينَ أُوتُوا۟ ٱلْكِتَٰبَ حِلٌّۭ لَّكُمْ وَطَعَامُكُمْ حِلٌّۭ لَّهُمْ ۖ وَٱلْمُحْصَنَٰتُ مِنَ ٱلْمُؤْمِنَٰتِ وَٱلْمُحْصَنَٰتُ مِنَ ٱلَّذِينَ أُوتُوا۟ ٱلْكِتَٰبَ مِن قَبْلِكُمْ إِذَآ ءَاتَيْتُمُوهُنَّ أُجُورَهُنَّ مُحْصِنِينَ غَيْرَ مُسَٰفِحِينَ وَلَا مُتَّخِذِىٓ أَخْدَانٍۢ ۗ وَمَن يَكْفُرْ بِٱلْإِيمَٰنِ فَقَدْ حَبِطَ عَمَلُهُۥ وَهُوَ فِى ٱلْءَاخِرَةِ مِنَ ٱلْخَٰسِرِينَ ﴿٥﴾
This day [all] good foods have been made lawful, and the food of those who were given the Scripture is lawful for you and your food is lawful for them. And [lawful in marriage are] chaste women from among the believers and chaste women from among those who were given the Scripture before you, when you have given them their due compensation, desiring chastity, not unlawful sexual intercourse or taking [secret] lovers. And whoever denies the faith - his work has become worthless, and he, in the Hereafter, will be among the losers.
Lawful relations are only through marriage, not by taking lovers.
Quran, Surah Al-Israa 17:32
وَلَا تَقْرَبُوا۟ ٱلزِّنَىٰٓ ۖ إِنَّهُۥ كَانَ فَٰحِشَةًۭ وَسَآءَ سَبِيلًۭا ﴿٣٢﴾
And do not approach unlawful sexual intercourse. Indeed, it is ever an immorality and is evil as a way.
Islam forbids what leads to zina, not only zina itself.
Jami' at-Tirmidhi 2165
Graded sahih... لا يخلون رجل بامرأة إلا كان ثالثهما الشيطان ...
"No man is alone with a woman except that Shaytan is the third of them."
Seclusion with a non-mahram is forbidden.
Sahih al-Bukhari 5233
Sahih... لا يخلون رجل بامرأة إلا مع ذي محرم ...
"No man should be alone with a woman except with a mahram present."
A mahram should be present when a man and woman meet.
Sahih Muslim 2658
Sahih... فالعينان زناهما النظر والأذنان زناهما الاستماع ...
"The zina of the eyes is looking, and the zina of the ears is listening."
Flirtatious looks and talk are sins in themselves.
Where the ruling is recorded
- Radd al-Muhtar (Ibn Abidin), Kitab al-Hazr wa al-Ibaha, chapter on looking and touching. Rules on looking at, speaking to and touching non-mahrams.
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.