Number one
Number one was a title affectionately given to an officer who was second in command, literally because the first officer was, in name, the commanding officer's "number one" man or woman.

Notable uses of "number one" 
Captain Christopher Pike and Spock referred to Lieutenant Commander Una Chin-Riley, the first officer of the  as "Number One". ()

Commander Michael Burnham was referred to as "number one" by Captain Philippa Georgiou and the crew of the . ()

Commander Saru was referred to as "number one" by Captain  aboard the . ()

Lieutenant La'an Noonien-Singh was made acting first officer during the 's mission to Kiley 279. Captain Pike referred to her as "number one". ()

In the mirror universe, Michael Burnham, while posing as , referred to  as "number one" aboard the . ()

Captain Picard typically referred to his first officer, Commander William T. Riker, as "number one" aboard the  and  (, et seq., ) 

Doctor Beverly Crusher once referred to Riker as "number one." ()

Rear Admiral Mark Jameson also once referred to Riker as "number one" while he sat in the first officer's customary chair on the bridge. ()

In 2365, when the crew prepared their ruse against the Ferengi, Picard said "Are you ready, number one?" and both Riker, on the , and Data, as acting first officer, answered him. ()

In 2366, the character based on Riker in Reginald Barclay's Three Musketeers-inspired holodeck program was addressed as "number one". ()

After Sarek and Picard mind-melded, Sarek referred to Commander Riker as "number one". ()

After his assimilation by the Borg, Picard, as Locutus, chillingly referred to Riker as "number one." () 

While he was trapped in the turbolift with the three 2368 Primary School Science Fair winners, Captain Picard referred to Marissa Flores as "number one." Some confusion came about later when both she and Riker responded to the title on the bridge. ()

While age regressed, Captain Picard posed as Commander Riker's son in order to route access to the ship's systems to the school classroom. When Riker agreed to do this, Picard slipped out of character and said, "Thank you, number one." However, he realized his mistake and recovered by saying, "He's my number one dad." ()

Notable "number ones"

Appendices

Appearances 
The term "number one" appears in the following:

Background information 
The first draft of the  "bible" created while the series was in development noted that this nickname was chosen as a homage to historical British Navy tradition. (). 

The nickname featured prominently in the first casting call for The Next Generation, sent out on 10 December . This document listed "NUMBER ONE (A.K.A. WILLIAM RYKER)", and all other references to this character were to "Number One" rather than "Ryker". (Star Trek: The Next Generation Companion, 2nd ed., p. 13).

Apocrypha 
In Peter David's  Vendetta, Captain Morgan Korsmo, captain of the  referred to his first officer, Commander Shelby, as "number one."

In her  Vulcan's Glory, TOS writer D.C. Fontana suggested Captain Pike called his first officer this because she was an Ilyrian colonist who was named "Number One," because she was the best intellect among her generation.

In novels set after , Worf has become Picard's first officer on the  and Picard immediately started referring to Worf as "number one," which privately made Worf a bit uncomfortable at first, as he thought of Riker when Picard would say that.

External link 
 

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