Was born on 8 October 1787 the son of Bhai Deva Singh and Mai Rajadi, professionally cloth-printers of Nurdin village, also known as Sarai Nurdin, 7 km northwest of Tarn Taran in Amritsar district of the Punjab. Deva Singh though poor was educated and well versed in the sacred texts. He sent his son, after preliminary education at home, to Amritsar where he became 'a pupil of Giani Sant Singh (1768-1832), a renowned man of letters and custodian of Sri Darbar Sahib.

After having studied Sikh Scripture and history, Sanskrit language and literature, poetics, philosophy and mythology at Amritsar for about 15 years, Santokh Singh moved to Buria, an old town on the right bank of Yamuna in the present Yamuna Nagar district of Haryana, some time before 1813, and established himself there as a writer, poet, and preacher. His patron was Dial Singh, also from a cloth-makers' family and an old acquaintance of the poet's father, who was serving as an army officer under Sardar Hari Singh, chief of Buria. Here Santokh Singh wrote his earlier works,. Nam Kosh, a versified Hindi translation of Amar Kosa, the famous Sanskrit dictionary, (completed in 1821), and Sri Guru Nanak Prakash, an epic poem consisting of 9,700 verses dealing with the life and teachings of Guru Nanak- (Completed in 1823). He had attained such repute as a poet and scholar that Bhai Udai Singh, chief of Kaithal, invited him in 1825 to join his court. Santokh Singh is said to have spent some time at Patiala also as an employee of Maharaja Karam Singh before going to Kaithal.

During his 18-year span at Kaithal, now a district town in Haryana, he wrote Garab Ganjani Tika (1829), an exhaustive philosophical commentary in Hindi prose on Guru Nanak's Japu, along with a critical appreciation of its poetic features (the work was meant to be a rejoinder to Anandghana's tika of the Japu); Vilmiki Ramayana (1834), a versified translation of the epic in chaste and refined Braj Bhasa ; translation of Atma Purana in Sadhukari prose (date not known) ; and his mangum opus, Sri Gur Pratap Suryodaya, popularly known as Gur Pratap Suraj Granth, a voluminous history of the Gurus in Braj Bhasa consisting of 51,820 verses written during 1835-43.

Bhai Santokh Singh was married during his stay at Buria to Bibi Ram Kaur of Jagadhri. Five sons and three daughters were born to them. Some of his descendants are now living at Patiala and at Kaithal. The poet died at Kaithal on 19 October 1843, soon after the completion of his Gur Pratap Suraj Granth, A shrine in honour of his memory was constructed at his native place, Sarai Nurdin, during the 1950's.

Sri Gur Pratap Suraj Granth
Bhai Santokh Singh's monumental work in Braj verse portraying in comprehensive detail the lives of the Ten Gurus of the Sikh faith and the career of Banda Singh Bahadur. Besides being an historical narrative of great significance, it is an outstanding creation in the style epic, and is the most voluminous of all poetic compositions in Hindi/Punjabi literature. Its language is Braj Bhasa which was the literary Hindi of that time though its script is Gurmukhi. Notwithstanding certain drawbacks which scholars with training in modern historiography may point out, it remains the most valuable source book on Sikh history of the period of the Gurus and, indeed, on the very roots of the entire Sikh tradition. For the massive flow of its poetry, the vast range of its figures and images and for the abundance of detail, Sri Gur Pratap Suraj Granth, Suraj Prakash in shorter, popular form, is worthy to rank with the classics in this genre.

The title of the main work carries a symbolic meaning summed up in the cosmic metaphor of suraj, i.e. the sun. The poet himself explains, "As the sun rises, the darkness of the night vanishes, thieves and thugs hide themselves, owls and bats go to slumber and the stars disappear, so with the advent of the Gurus, the rays of their spiritual light spread all around dispelling the darkness of ignorance."

The work is divided into two parts. The first, Sri Gur Nanak Prakash in two sections, is the story of the life of Guru Nank. The second, Sri Gur Pratap Suraj proper, is divided into portions, rut (season), according to the twelve signs of the zodiac, sub-divided into chapters called arisu (rays). In the Sri Gur Nanak Parkash portion, the style of the narrative tends to be more elaborate, with many a stanza given to homage to the Gurus, the Guru Granth Sahib and to the patron deities of learning. The latter part, which deals with the lives of succeeding nine Gurus and Banda Singh Bahadur, contains 51,829 verse pieces in 22 cantos. The expression here is less rhetoric. Both the parts are further sub-divided into numerous sections according to the episodes narrated, each named after the sun's course, viz. the twelve zodaical signs, the six seasons and the two solstices (winter and summer solstices) which in turn comprise 1151 sunbeams, each one comprising a chapter. The phrase and imagery in both the parts of the book generally require expert explanation. This has been provided, painstakingly and exhaustively, by Bhai Vr Singh in a 14-volume annotated edition brought out in 1927-35. Bhai Vr Singh has also added notes where necessary.

It is usual for gianis (learned scholars) to hold serial discourses on the text of Suraj Prakash in gurdwaras, normally in the afternoons or evenings.