Masjid Ul Nur is a longstanding Sunni Muslim mosque and community congregation in Longdenville, Trinidad and Tobago. Located in Longdenville, it has served as a center for worship, Islamic education, and community life for more than a century, with origins dating to around 1918. 

The congregation began to serve Muslims living and working in the Longdenville area, including those employed on nearby sugar estates, clay works, and agricultural lands. The land for the original mosque was donated by Ameer Kanhai (Kanhai Meah), and the first building was a modest tapia structure with a thatched roof before later being rebuilt in more permanent materials. 

During the 1940s, the mosque experienced a period of decline following internal divisions, but community leader Haji Shair Ali played a central role in reviving the congregation. He helped organize religious instruction, supported the appointment of imams, and became an influential figure in the mosque's development until his death in 1989. 

The mosque functions as an active place of worship offering:

• Five daily prayers (Salaah)

• Islamic classes (Maktab)

• Religious programs and community events

It has also maintained ties with Anjuman Sunnat-ul-Jamaat Association (ASJA), participating in regional educational programs, Qur'anic recitation competitions, and lectures by visiting Islamic scholars over several decades. According to the mosque listing, the current imam is Salahudeen Mohammed. 

The mosque has expanded significantly over time. Improvements have included:

• Construction of a dedicated masjid hall.

• Enclosure of surrounding corridors.

• Addition of an upper-level men's prayer area around 2005–2006.

• Renovations to the hall ceiling in 2009.

• Expansion and modernization of the hall, kitchen, corridors, and women's facilities in 2018. 

Masjid Ul Nur is recognized as one of Trinidad and Tobago's historic mosques and is included in discussions of the country's Islamic heritage. Its history reflects the growth of Muslim communities established by Indo-Trinidadian settlers after indentureship and the important role local congregations have played in preserving religious education and community life across generations.