Garibaldi's father, Alfredo, was a marine with EarthForce under command of General Richard Franklin during the war against the Dilgar (GROPOS).  In his time with security, Garibaldi has worked on Europa, Orion 4 and Mars (Survivors), where he met Jeffrey Sinclair (the comic Shadows Past and Present).  He survived an alcohol addiction (Survivors) to develop a love for classic 20th Century Warner Bros cartoons - he even has a poster of Daffy Duck in his quarters.  His inability to trust almost anyone mixed with his love of his job makes him an effective Security Chief on Babylon 5, although all of these things resulted in his eventual split from girlfriend Lise Hampton (A Voice in the Wilderness, Babylon Squared).  Although it is unknown what he did during the Earth-Minbari War, he was still undergoing counselling for his "traumatic experiences" by 2259 (The Long Dark).

After he was shot in the back by one of his own men when he discovered a plot to kill President Santiago (Chrysalis), he considered resigning his commission (Revelations).  He also objected when Sheridan detained Morden for no legitimate reason and threatened to resign his commission (In the Shadow of Z'ha'dum).  During his readings of the Narn holy book, The Book of G'Quan, he found a possible weapon against the Shadows (Ship of Tears).  He even made a significant contribution to the overall content of G'Kar's own magnum opus, The Book of G'Kar (No Compromise, Meditations on the Abyss).

He was kidnapped by the Shadows after they converged on Babylon 5 (Z'ha'dum), to be subjected to conditioning and interrogation by Psi Corps (Whatever Happened to Mr Garibaldi?) before he was rescued (The Summoning) and finally resigned his commission once and for all (Epiphanies).

He commenced work as a private investigator to be employed by William Edgars (Racing Mars) to smuggle secret goods past Babylon 5 customs (Conflicts of Interest, Moments of Transition) before finally returning to Mars to assist Edgars in bringing down Sheridan (The Exercise of Vital Powers, The Face of the Enemy).  Bester finally released him from his conditioning when he provided him with the information he needed about Edgars (The Face of the Enemy).

To make up for his behaviour, he helped rescue Sheridan (Between the Darkness and the Light) and stage the rebellion against Earthforce from Mars (Endgame).  He returned to Babylon 5 to act as a personal security advisor to President Sheridan (No Compromises), to the chagrin of the new station commander, Captain Lochley (No Compromises, Learning Curve, Strange Relations).

His lust for revenge toward Bester is hampered by the fact that the Psi Cop planted within him an "Asimov" - a basic mental block preventing Garibaldi from attacking or killing him (Phoenix Rising).  His frustration at this is vented by his return to alcoholism (Phoenix Rising, The Ragged Edge, Meditations on the Abyss, Darkness Ascending).

When he is suspended from the Alliance for his drinking, Lise offers him joint management of Edgars Industries.  With the power available to him in his new position, he strikes a deal with Lyta Alexander to undermine Psi-Corps (Wheel of Fire).   He marries Lise Hampton shortly before leaving Babylon 5 (Objects in Motion) and makes his first order of business is to investigate Edgars' "black projects" commissioned by President Clark (Objects in Motion, The River of Souls).  He and Lise soon have a daugher, Mary (Sleeping in Light, A Call to Arms).

After the Telepath War, and now free of the "Asimov", Garibaldi began a personal mission to track down Bester to exact his revenge; he finally completed his task in 2271, capturing Bester in Paris to face trial and punishment for his crimes (the novel Final Reckoning).

Even five hundred years after his death, he managed to save the Alliance from being perceived as an oppressive fascist state by human forces during a civil war (The Deconstruction of Falling Stars).

Played by Jerry Doyle, who married actress Andrea Thompson (Talia Winters) in 1995, had a son, Al, and divorced in 1997.  He has appeared in the TV series Moonlighting and Sliders.