I heard the messenger of Allah ﷺ say: Verily, al-Islam is founded on five (pillars): testifying the fact that there is no god but Allah, establishment of prayer, payment of Zakat, fast of Ramadan and Pilgrimage to the House. (Using translation from Muslim 16d)
قَالَ رَسُولُ اللهِ ﷺ بُنِيَ الْإِسْلَامُ عَلَى خَمْسٍ شَهَادَةِ أَنْ لَا إِلَهَ إِلَّا اللهُ وَإِقَامِ الصَّلَاةِ وَإِيتَاءِ الزَّكَاةِ وَحَجِّ الْبَيْتِ وَصَوْمِ رَمَضَانَ