Paramount Pictures is a film studio that has been owned by American media conglomerate Viacom since 1994.
The studio held television rights to the original Hawaii Five-O series starting in 1995 after absorbing Viacom's syndication operations; Viacom had been the syndicator of the series since its 1971 spin-off from CBS.
Following Viacom's purchase of CBS in 2000, Paramount gained home video rights to the series and the CBS library in general which previously had been held by 20th Century Fox through a joint venture with CBS.
It wouldn't be until 2007 that Paramount distributed its first home video release of Hawaii Five-O in the form of the first season on DVD, after Viacom renamed itself CBS Corporation and spun off the Paramount movie studio and most of its cable assets as a new Viacom (as National Amusements controlled both companies, Paramount retained its home video rights to the CBS library), in the process Paramount's TV operations folded into those of CBS.
Since 2011, Paramount has also distributed the reboot series on home video on CBS' behalf, with Blu-ray releases in addition to DVD releases of each of the first six seasons.