Polina Semyonovna Zhemchuzhina (Russian: Поли́на Семё́новна Жемчу́жина) (1897–1970) was a Soviet politician and the wife of the Soviet foreign minister Vyacheslav Molotov.

Born Perl Karpovskaya to the family of a Jewish tailor in the village of Pologi, in the Aleksandrov uyezd of Yekaterinoslav Governorate (today Zaporizhia Oblast, Ukraine), she joined the Russian Social Democratic Labour Party of Bolsheviks in 1918 and served as a propaganda commissar in the Red Army during the Russian Civil War. As a communist, she went by the surname Zhemchuzhina, which, like her birth name Perl in Yiddish, means "pearl".

In 1921, she married Vyacheslav Molotov, by then a member of the Central Committee of the Communist Party of the Soviet Union (CPSU). She also made a successful career in the Soviet hierarchy, serving in the Narkomat of Food Industry under Anastas Mikoyan, to become in 1939 the first female councillor of Narkom (of Fishing Industry) in the government of the Soviet Union, and was elected a candidate to the Central Committee that year.

During the 1920s, her sister emigrated to the then-British Mandate of Palestine. According to historian Zhores Medvedev, Stalin was highly suspicious of Zhemchuzhina. He thought that she negatively influenced Molotov, and he recommended Molotov to divorce her.

Her brother Sam Carp was a successful businessman in the USA (Montefiore, Stalin n282)

The Molotovs shared an apartment with the Stalins. Zhemchuzhina and Stalin's wife Nadezhda Alliluyeva became close friends. In November 1932, Zhemchuzhina followed and calmed Alliluyeva out from a dining room after being publicly chastised by Stalin in the company of friends. The next morning Alliluyeva was found dead of an apparent uicide. This event is believed to have fueled a secret hatred from Stalin towards Zhemchuzhina.

In a secret meeting of the Politburo on August 10, 1939, the agenda item number 33, "Regarding Comrade Zhemchuzhina", her alleged "connections to spies" led to a request to verify that information by the NKVD. As it was customary during the Great Purges, many of her coworkers were arrested and questioned, but the "evidence" (frequently acquired by force) against her was so contradictory that (on October 24) the Politburo concluded the "allegations against comrade Zhemchuzhina's participation in sabotage and spying... to be considered slanderous." However, she was severely reprimanded and demoted for unknowingly keeping contacts with "enemy elements thereby facilitating their spying missions." In February 1941, she was taken off the list of the candidates to the Central Committee.

In the Eastern Front of World War II, Zhemchuzhina actively supported the Jewish Anti-Fascist Committee (JAC) and befriended many of its leading members, most notably Solomon Mikhoels. She frequently attended performances by the Moscow State Jewish Theatre.

Polina Zhemchuzhina befriended Golda Meir, who arrived in Moscow in November 1948 as the first Israeli ambassador to the USSR. Fluent in Yiddish, Zhemchuzhina acted as translator for a diplomatic meeting between her husband, Vyacheslav Molotov, the Soviet Union's foreign minister, and Meir.

She was arrested for treason in December 1948, as she openly supported the idea of granting the region of Crimea to the Jewish community, consequently divorcing with Μolotov . The sentence was five years in a labour camp. She was eventually reunited with her husband by Lavrentiy Beria, after the death of Stalin, in March 1953. Her first question was "How's Stalin?" Upon being told he had died only days before, she fainted.

Happily and lovingly reunited, Polina Zhemchuzhina and her husband lived as unrepentant Stalinists in the Granovsky apartment block near the Kremlin. She died of natural causes in 1970.