*Campylobacter jejuni* subsp. *jejuni* infections are a leading cause of foodborne gastroenteritis and the most prevalent antecedent to Guillain-Barré syndrome (GBS). Penner serotype HS:19 is among several capsular types shown to be markers for GBS. This study describes the genome of *C. jejuni* subsp. *jejuni* HS:19 Penner reference strain RM3420.