Captain Georgiou called Michael Burnham “Number one,” on the USS Shenzhou and Captain Lorca called Saru “Number one” on Discovery.
Discovery honored this tradition in the first season, too. The idea that a captain would call their first officer “Number One” comes from the naval tradition, and was most famously used by Captain Picard as a nickname for Riker in The Next Generation. Read more: The 15 Best Worst Episodes of Star Trek: The Original Series
