Sekolah Menengah Sains Selangor is actually located within the boundaries of the Federal Territory of Kuala Lumpur, despite what its name suggests. It is one of the earlier SM Sains schools in the country, hence its name bearing or representing the State of Selangor, prior to the formation of the Federal Territory of Kuala Lumpur.

SMSS is a co-ed school, with students from all the states in Malaysia. The pioneer batch of students which were made up of Form 1 and 4 started in 1973 temporarily placed for a year at three other different schools in High School Kelang, High School Kajang, Sek. Men. Sultan Abdul Aziz, Kajang for the first formers. Meanwhile, the form four students were temporarily placed in Sekolah Alam Shah and Sek. Men KGV, Taiping. They were reunited at the new school in 1974 as Form 2 and 5 students. Later intakes were mostly from Form 1 based on their UPSR excellence, with a trickle coming in at Form 4 based on their PMR results.

After more than 34 years of establishment, SMSS now stands tall and proud alongside other more established SBPs like its own sibling rivals like Sekolah Menengah Sains Tengku Muhammad Faris Petra and Sekolah Menengah Sains Raja Tun Azlan Shah. They find themselves locking horns with each other during yearly competitions such as rugby, hockey, debate, wind orchestra and other events organized by the SBP Sector under MOE. Needless to say, Sekolah Menengah Sains Selangor has won their fair share of these competitions, and they would have given a more than worthy challenge for their opponents. The school have been an off-site team challenge for MasterChef Malaysia season 2.[3]

In 2013, in conjunction with the school 40 years celebration, the school were honoured to host the Fully Residential School Excellence Day, while the school also hosted FRSIS (Fully Residential Schools International Symposium) in 2016.