The word(s) "monotheism" appears 283 time(s) in 267 verse(s) in Quran in Mohsin Khan translation.

(1) This is the Book (the Qur'an), whereof there is no doubt, a guidance to those who are Al-Muttaqun [the pious believers of Islamic monotheism who fear Allah much (abstain from all kinds of sins and evil deeds which He has forbidden) and love Allah much (perform all kinds of good deeds which He has ordained)].

(2) Those who break Allah's Covenant after ratifying it, and sever what Allah has ordered to be joined (as regards Allah's religion of Islamic monotheism, and to practise its laws on the earth and also as regards keeping good relations with kith and kin ), and do mischief on earth, it is they who are the losers.

(3) And those who believe (in the Oneness of Allah تعالى - Islamic monotheism) and do righteous good deeds, they are dwellers of Paradise, they will dwell therein forever. (See V. 2:257)

(4) Yes, but whoever submits his face (himself) to Allah (i.e. follows Allah's Religion of Islamic monotheism) and he is a Muhsin then his reward is with his Lord (Allah), on such shall be no fear, nor shall they grieve. [See Tafsir Ibn Kathir ].

(5) Never will the Jews nor the Christians be pleased with you (O Muhammad صلى الله عليه وسلم) till you follow their religion. Say: "Verily, the Guidance of Allah (i.e. Islamic monotheism) that is the (only) Guidance. And if you (O Muhammad صلى الله عليه وسلم) were to follow their (Jews and Christians) desires after what you have received of Knowledge (i.e. the Qur'an), then you would have against Allah neither any Wali (protector or guardian) nor any helper.

(6) And who turns away from the religion of Ibrahim (Abraham) (i.e. Islamic monotheism) except him who befools himself? Truly, We chose him in this world and verily, in the Hereafter he will be among the righteous.

(7) And this (submission to Allah, Islam) was enjoined by Ibrahim (Abraham) upon his sons and by Ya'qub (Jacob) (saying), "O my sons! Allah has chosen for you the (true) religion, then die not except in the Faith of Islam (as Muslims - Islamic monotheism)."

(8) And they say, "Be Jews or Christians, then you will be guided." Say (to them O Muhammad صلى الله عليه وسلم), "Nay, (we follow) only the religion of Ibrahim (Abraham), Hanifa [Islamic monotheism, i.e. to worship none but Allah (Alone)], and he was not of Al-Mushrikun (those who worshipped others along with Allah - see V.2:105)."

(9) Thus We have made you [true Muslims - real believers of Islamic monotheism, true followers of Prophet Muhammad صلى الله عليه وسلم and his Sunnah (legal ways)], a just (and the best) nation, that you be witnesses over mankind and the Messenger (Muhammad صلى الله عليه وسلم) be a witness over you. And We made the Qiblah (prayer direction towards Jerusalem) which you used to face, only to test those who followed the Messenger (Muhammad صلى الله عليه وسلم) from those who would turn on their heels (i.e. disobey the Messenger). Indeed it was great (heavy) except for those whom Allah guided. And Allah would never make your faith (prayers) to be lost (i.e. your prayers offered towards Jerusalem). Truly, Allah is full of Kindness, the Most Merciful towards mankind.

(10) O you who believe (in the Oneness of Allah - Islamic monotheism)! Eat of the lawful things that We have provided you with, and be grateful to Allah, if it is indeed He Whom you worship.