Star Trek: Voyager's Kathryn Janeway (Kate Mulgrew) deserves the honor of being thought of as the Borg's greatest enemy, a distinction that is often given to Jean-Luc Picard (Patrick Stewart). Janeway was the captain on Voyager for all seven seasons, holding the distinction of being the first female captain to lead a Star Trek TV show. Despite the Borg being most closely associated with Star Trek: The Next Generation, seasons 4-7 of Voyager also heavily featured them as the main antagonist, with the crew of the USS Voyager coming into conflict with the Collective and the Borg Queen on multiple occasions during their journey through the Delta Quadrant.
Both Captain Picard and Captain Janeway had their fair share of dealings with the Borg, and there is good reasoning for both to be considered the Borg's greatest enemy. However, in Star Trek: Voyager's series finale, "Endgame", it was Janeway who dealt the Collective the ultimate blow in the form of a neurolytic pathogen. A time-traveling Admiral Janeway allowed the Borg Queen (Alice Krige) to assimilate her and subsequently infect the entire Collective with the pathogen. The effects of this attack weren't explored fully until the series finale of Star Trek: Picard, which finished what Voyager had started and finally killed the ruined Queen and her Collective once and for all.
Why Janeway Was The Borg’s Greatest Enemy, Not Picard
Janeway's delivery of the pathogen in Star Trek: Voyager's series finale ultimately places her above Jean-Luc Picard as Borg's greatest enemy. The pathogen completely decimated the Borg Queen and left the entire Collective in ruins, and while Picard and the crew of the USS Enterprise-D dealt the final killing blow, it was Janeway who originally crippled the Collective permanently. What Picard accomplished in terms of killing the Queen and destroying the last cube was crucial, but in a sense, Picard was simply cleaning up the last of the mess Janeway's pathogen had made of the Borg.
Additionally, while Jean-Luc Picard may have thought of himself as the Borg Queen's enemy, the Borg Queen saw Picard as a potential ally for nearly the whole time they were at odds. The Queen never stopped trying to get Picard to rejoin the Collective as Locutus of Borg, and ultimately used Picard's DNA and his son, Jack Crusher (Ed Speleers), to enact her final desperate plan to destroy Starfleet. Janeway didn't have this same history with the Borg Queen, making the two more straightforward enemies from the start. This was cemented by the encounters they had and Janeway's ruthless attempts to destroy the Queen, which ultimately succeeded.
Janeway Was Picard Season 3’s Most Important Missing Character
Because Star Trek: Picard season 3 acted as a conclusion to Star Trek: Voyager's finale, Janeway was extremely important to the season's storyline. Janeway's connection to what happened to Borg wasn't the only way she showed up in Picard season 3, however. The now-Admiral Janeway was name-dropped several times throughout the season in connection with Frontier Day, and Star Trek: Picard showrunner Terry Matalas revealed that he wanted to include an actual Janeway cameo in Picard's finale, possibly having her be the one to promote Seven of Nine (Jeri Ryan) to Captain instead of Tuvok (Tim Russ).
The reasons that Matalas was unable to include Janeway came down to budgetary constraints and not wanting to step on Star Trek: Prodigy's toes, but despite not appearing, Janeway was almost an honorary character in Star Trek: Picard season 3. Picard's final twist wouldn't have even been possible if it weren't for what Janeway did in Star Trek: Voyager, and cemented the fact that Janeway became the Borg's greatest enemy rather than Picard. If Admiral Janeway continues to make appearances in Star Trek's 25th century as the timeline moves forward, her ultimate defeat of the Borg should be acknowledged.
Star Trek: Picard season 3 is available to stream on Paramount+.