The lighting up took place as the sun set and was followed by a vigil in Hurst Street, at the heart of Birmingham’s Gay Quarter.
Almost 50 people were killed and another 53 were enjured after a heavily-armed gunman released fire at Pulse, a gay nightclub in Orlando, Florida.
The rainbow flag is a symbol for the LGBT (Lesbian, Gay, Bisexual and Transgender community).
The Library of Birmingham has previously lit up in light of the Brussels and Paris attacks.
