The official opening of the school was held October 5th, 1977 with the following people present: Dr. Pat McGeer, Minister of Education, Chief Delbert V. Guerin, Musqueam Indian Reserve, Mr. Smedly, Chairman of the School Board, Susan Howatt, Student Council Prime Minister, W. Collins and Brockington, architects, Superindendent of Schools, G. Moulds, and Principal A.E. Coleman.
The school name was determined by a contest where students and members of the community sent in their suggestions. The Board of School Trustees chose the name 'Seaquam' which means 'the sun' or 'sunshine' in the Musqueam language.
Seaquam Secondary School opened on September 6, 1977. The original teaching staff of thirty-seven increased in September, 1977 to forty-one because one hundred more students enrolled than expected. In the initial year, the school enrolled six hundred thirty-three students in grades 7 to 11. Then grade 12 was added, and grade 7 was dropped to create our present 8-12 configuration. It is interesting to note that some of the teaching staff remain from the original group. Since September 1977, school enrollment has increased to over thirteen hundred students, with 70 teaching staff.
Seaquam Secondary has developed into a succesful and comprehensive school with a reputation for having strong programs in the areas of academics, athletics, student leadership, vocational preparation, and the visual and performing arts.
The commitment to scholastic excellence by teachers and students at the school is illustrated by student success. Seaquam Secondary graduates have earned places in post-secondary institutions across Canada and the United States. Many of those same students have been awarded prestigous scholarships and bursaries in recognition of those academic achievements.
Mr. A. E. Coleman was the first Principal until 1991 when he was replaced by Mr. E. Lorenz. Following Mr. Lorenz's retirement, Mr. P. Arcand was appointed principal in 1994. Mr. Arcand retired in 1998 when Mr. Des Lauriers became principal. Mr D. Fisher, arriving in 2002 from North Delta Secondary, retired in 2005. His successor, Mrs. C. Thornicroft, had served as an Assistant Superintendent of Delta School District, and prior to her destination at Seaquam led Sands Secondary.  In 2006, Gord Collings came from South Delta returning to the school he was once a councilor.
Our current principal as of 2010, Ms. Morgan Kyle, was a longtime adminsitrator in Surrey and also Human Resource manager at the Delta School District.