The two veteran players signed contract extensions with the Saskatchewan Roughriders on Monday, a day before they were scheduled to become free agents.
Jackson, a five-foot-eight, 185-pound international defensive back, enters his eighth CFL season and fifth with Saskatchewan. Jackson had four interceptions last year and also led the CFL in kickoff-return yards (954), missed field-goal return yards (267) and total return yards (1,531).
Regimbald, a six-foot-one, 225-pound linebacker from Montreal, returns for his third CFL season. He was selected in the fifth round, No. 35 overall, in the 2012 CFL draft.
The Riders also dealt the rights to national kicker John Mark to the Ottawa Redblacks for a 2016 draft pick.