Holy Trinity Cathedral, Port of Spain

The Red House is the seat of Parliament in Trinidad and Tobago. The architectural design of the Red House is of Beaux-Arts style. The original building was destroyed in the 1903 Water Riots and was rebuilt in 1907. The Red House is located centrally within the capital city Port of Spain. It is currently used as a meeting place for parliament and elections and for political uses. In July 1990, the Red House was the site of the Jamaat al Muslimeen coup attempt, during which the Prime Minister and other members of the government were held hostage for six days and 24 people were killed.

The Parliament of Trinidad and Tobago is the legislative branch of the Government of Trinidad and Tobago. The Parliament is bicameral. Besides the President of Trinidad and Tobago, it is composed of the House of Representatives, which is composed of the Speaker of the House of Representatives in addition to 41 directly elected members serving a five-year term in single-seat constituencies, and the Senate which has 31 members appointed by the President: 16 Government Senators appointed on the advice of the Prime Minister, 6 Opposition Senators appointed on the advice of the Leader of the Opposition and 9 Independent Senators appointed by the President to represent other sectors of civil society. It is at present the only parliament in the world with an incumbent female President, President of the Senate, Speaker of the House of Representatives and Leader of the Opposition and made history by appointing the Caribbean's first and only transgender parliamentarian on 15 February 2022. As of 20 April 2021, there are only 24 female members, or 32.9% and eight members born in Tobago or 11.0%.

The House of Representatives is the elected lower house of the bicameral Parliament of Trinidad and Tobago, along with the President and Senate of Trinidad and Tobago. The House of Representatives sits at the Red House. It has 41 members, each elected to represent single-seat constituencies. The Parliament is elected with a five-year term, but may be dissolved earlier by the President if so advised by the Prime Minister. After an election, the person commanding the support of the most members of the House is appointed Prime Minister and asked to form a government. Five constituencies were added in the 2007 election; there were only 36 constituencies prior to 2007. There are now 41 constituencies. The Presiding Officer of the House of Representatives is the Speaker of the House, who can either be one of the elected 41 members, or come from outside. This has implications for the calculation of special majority votes (42 members instead of 41). As of 20 April 2021, there are only 12 female members (28.6%), and three members born in Tobago (7.3%).

Nicholas Tower, situated on Independence Square, Port of Spain, Trinidad and Tobago is the fifth tallest building in Trinidad and Tobago. It has an elliptical floor plate and stands 21 floors tall and 88 Meters high. Construction was completed in 2003 and each floor, 8,000 square feet (700 m2) of space, was rented out at a cost of $96,000 a month (as of 2005). It is a blue glass tower. The building was constructed on the site of the Trinidad Union Club, a 136-year-old private club which occupied the penthouse suite of the Nicholas Tower until 2015. Major tenants of Nicholas Tower include: The Trinidad and Tobago Stock Exchange, a former tenant of the old Union Club building (as of 2023) Caribbean Airlines (The national airline of Trinidad and Tobago) American Airlines Continental Airlines Ministry of Trade and Industry Ministry of Community Development, Culture and the Arts Office of the Prime Minister InvesTT (former tenant) Economic Diversification Board (EDB) of the Ministry of Planning Flow MoneyGram

The Government Campus Plaza is a government complex on Richmond Street and Wrightson Road in Port of Spain, Trinidad and Tobago. Completed in May 2017, the Government Campus Plaza provides public access to the services of four major government ministries and agencies. Across from the POS International Waterfront Centre on Wrightson Road on a 1,154,000 sq ft (107,200 m2) quadrangular piazza, the Government Campus Plaza provides office accommodation, parking, and a public plaza with manicured gardens and entertainment space. In the plaza, just below the outdoor 40 ft × 70 ft (12 m × 21 m) screen mounted on one of the plaza's two 23-storey towers, is an outdoor performance area for cultural festivals and performances.

Eric Williams Plaza, also known as the Eric Williams Financial Complex, located on Independence Square, Port of Spain, consists of two of the tallest buildings in Trinidad and Tobago, as well as in the English-speaking Caribbean. It consists of a pair of skyscrapers 22 stories high and 302 ft (92 m) tall, locally known as the "Twin Towers". Construction on the complex started in 1979 and ended in 1986. The complex was officially opened on March 29, 1986. The architect who managed the construction was Anthony C. Lewis Partnership. The Eric Williams Plaza was named after Eric Williams, the first prime minister of Trinidad and Tobago. The first tower houses the Central Bank of Trinidad and Tobago while the second tower houses the Ministry of Finance. The first tower's official name is Eric Williams Financial Tower and the second tower's official name is the Central Bank Tower. The building surrounding the towers is the old Central Bank. The old Central Bank building has gold and currency vaults, administrative areas, an auditorium and a concert hall. It is one of the finest facilities in the country. It is also part of the complex. Both towers contain building security, communications, and life-safety systems. The towers have an earthquake resistant design. The cross braces and core walls in both towers are designed to take earthquake forces with the former taking 15% of the forces and the latter taking 85%. Additionally, great care was taken in the detailing of the reinforcement. The thickness of the basement under each tower is 25'. The pile cap under each tower is a cellular raft which is a combination of 9' × 6' beams and an 18" slab. Water storage for the complex is located in the basements of the towers. The building is located on the Brian Lara Promenade, Independence Square (formerly Marine Square) in downtown Port of Spain. It was the tallest building in Trinidad and Tobago until the Nicholas Tower was constructed by businessman Issa Nicholas. From 1993 to January 1999, the office of the Prime Minister was housed here; in 1999 it was returned to the Whitehall.

The Cathedral of the Immaculate Conception is a Catholic cathedral in Port of Spain, Trinidad and Tobago. It is the seat of the Archdiocese of Port of Spain. Construction started in 1816 and it was completed in 1851. The same year the cathedral was given the honorary status of a minor basilica.

Fort San Andres is the last surviving fortification from the period of the Spanish Occupation of Trinidad, which came to an end in 1797 with the capture of the island by the British. As early as 1733, a fortification called Fort San Andres was planned to replace a redoubt of fascines and earth, which was the only defense to Port of Spain. This however was not completed until 1787. The redoubt was located more or less where Royal Bank now stands. Port of Spain or as it was known to the Spanish, Puerto de los Hispanioles, initially was restricted to a few streets east of the St. Ann's or Tragarete River which at that time ran west along what is now Park Street and south to the foreshore through what is now Woodford Square and Chacon Street. St. Ann's River, now better known as the Dry River, was diverted to its present course by the Spanish Governor Chacón and completed in 1787. The new fort was constructed as a mole linked to the mainland by a wooden bridge. The fort mounted five cannon and was "useful in maintaining good order among shipping anchored off-shore". In 1845, the Port of Spain Town council approved the filling of the Port of Spain waterfront to the northern side of Fort San Andres. Late in the nineteenth century the shoreline was again filled to its present line, completely land-locking the Fort. The Fort fell into disuse and later a structure was built on the old fort to house the Harbour Master and various other government offices, including the Police Service Traffic Branch. In 1995 the building was restored and converted to a museum of the City of Port of Spain. Several of the original cannons survive and the foundations bear the date 1785.

The National Academy for the Performing Arts (NAPA) is a cultural and performing arts complex located in Port of Spain, Trinidad and Tobago. Established in 2009, NAPA serves as a hub for the development and promotion of the performing arts in the country, providing facilities for education, rehearsals, and performances. NAPA’s contribution to the cultural landscape of Trinidad and Tobago has been recognized with multiple awards. It has garnered praise not only for its architectural design but also for its impact on the local arts scene.

St. Mary's College (CIC, which stands for College of the Immaculate Conception) is a government-assisted selective Catholic secondary school located in Port of Spain, Trinidad and Tobago.

St. Joseph's Convent, Port of Spain is a government-assisted all-girls Roman Catholic secondary school in Port of Spain, Trinidad and Tobago. It was founded in 1836 by Sisters of St. Joseph of Cluny, and is the oldest continuous secondary school in Trinidad and Tobago. It celebrated its 180th anniversary in 2016. The school is one of the best performing schools in the Caribbean in both the Caribbean Secondary Education Certificate (CSEC) examinations and Caribbean Advanced Proficiency Examinations (CAPE) examinations. The school is governed by a Board of Management appointed and chaired by the Archbishop of Port of Spain.

The National Trust of Trinidad and Tobago is managed by an eleven-member Council of different expertise and backgrounds. Five members are elected to the position, and six are ministerial appointments. Its offices are located in Port of Spain in Trinidad.