Garissa University College was targeted by the militant organisation in April 2015.
The terror group singled out Christians to be killed during a 16-hour siege, which ended with four gunmen being shot dead.
Staff have returned to work nine months after the attack with students to return on Monday.
Army and police officers have been posted to entrances to increase security amid fears of another attack.
The majority of students at the university at the time of the attack have moved to different campuses and will not return.
Elgon dormitory, where most of the Christians were murdered, will reopen after a refurbishment.
Al-Shabaab has been behind a number of attacks in Kenya with many churches targeted.
The group is angry at the presence of Kenyan troops in neighbouring Somalia.