The Doctor's spouses

The Doctor was known to have had a number of spouses.

Affairs
The Tenth Doctor told Sally Sparrow that he was "rubbish at weddings, especially [his] own". (TV: Blink)

The First Doctor was accidentally engaged to Cameca in the 15th century when he drank cocoa with her. (TV: The Aztecs)

An earlier incarnation had been wed (PROSE: Cold Fusion) to Patience and they were said to have had a number of children and grandchildren. (PROSE: The Infinity Doctors)

After Gallifrey was destroyed in the War in Heaven, the Eighth Doctor married Scarlette in order to ceremonially tie himself to the planet Earth. (PROSE: The Adventuress of Henrietta Street)

In one future stemming from the Eighth Doctor's life, (PROSE: The Tomorrow Window) the Ninth Doctor was engaged to be married to Emma, the only traveling companion he had ever "had". However, an incident which caused the Doctor to undergo four regenerations in quick succession resulted in Emma calling off her marriage to the female Thirteenth Doctor. (TV: The Curse of Fatal Death)

The Tenth Doctor romanced and later married Elizabeth I. (TV: The End of Time, The Day of the Doctor, PROSE: Suspicious Minds) She later declared him an enemy after he failed to return as promised. (TV: The Shakespeare Code) The Tenth Doctor implied he had been married several times prior to Queen Elizabeth, as he remarked to Sally Sparrow about being "rubbish at weddings, especially [his] own". (TV: Blink) In his eleventh incarnation, the Doctor accidentally became engaged to Marilyn Monroe, and married her the same night in what he later claimed was not a real chapel. (TV: A Christmas Carol)

River Song often hinted that she and the Doctor had a physical relationship somewhere in her past and his future relative to the Eleventh Doctor's encounter with the Silence in Florida. (TV: Silence in the Library / Forest of the Dead, The Time of Angels / Flesh and Stone, The Pandorica Opens / The Big Bang, Day of the Moon) The Eleventh Doctor, operating a Teselecta shaped like himself, performed a "quick version" of a wedding ceremony with River because they were in the middle of a combat zone in an alternate reality. They repeatedly referred to each other as husband and wife after the ceremony. (WC: Asylum of the Daleks Prequel, TV: The Wedding of River Song, The Angels Take Manhattan, The Name of the Doctor, The Time of the Doctor, The Husbands of River Song, AUDIO: The Boundless Sea, Five Twenty-Nine, The Eye of the Storm, PROSE: Suspicious Minds)

According to Clara Oswald, by the time of the Doctor's twelfth incarnation, he had been "married four times, all deceased". (TV: Death in Heaven)

Other references
While posing as a human, the Tenth Doctor told Florence Finnegan that he had said to his wife that he would recommend the Royal Hope Hospital to anyone. (TV: Smith and Jones)

The Tenth Doctor and Donna Noble were mistaken for a married couple by Lobus Caecilius (TV: The Fires of Pompeii) and by Solana Mercurio. (TV: Planet of the Ood) On both instances, they were quick to correct the misconception to the point that they would tell Agatha Christie as such when she had identified them simply as a couple, ascertaining that they were not married due to the lack of a wedding ring. (TV: The Unicorn and the Wasp) Donna had vehemently rejected the prospect of "mating" with the Doctor. (TV: Partners in Crime)

Behind the scenes

 * David A. McIntee once pitched a Fifth Doctor novel which would instead have revealed the Doctor and the Master as former spouses, in a plotline allegedly inspired by War of the Roses. The pitch was refused with a "death-stare" from Gary Russell.
 * Steven Moffat, in his production notes column in DWM 482, speculated that the Doctor's first spouse out of the four mentioned in the television story Death in Heaven was a woman who was married to the First Doctor for a long time on Gallifrey and bore the Doctor's children. He claimed "Mrs Who No 1" was never mentioned by the Doctor nor has he ever discussed her.