Joseph Stalin was elected as the General Secretary of the Central Committee of the CPSU in April 1922 during the 11th Congress of the Party. Between then and until his death, he asked to be relieved of his duties as General Secretary a total of four times — all of which were rejected.

On Lenin’s motion, the Plenum of the Central Committee, on April 3, 1922, elected Stalin … [as the] General Secretary of the Central Committee, a post at which he has remained ever since. Alexandrov, G. F. Joseph Stalin; a Short Biography. Moscow: FLPH, 1947, p. 74

Stalin’s first attempt at resignation (likely in 1925) from the post of General Secretary was at a meeting of the Central Committee after the 13th Congress (held in May 1924). This was rejected unanimously by all the delegations, including Trotsky. Stalin remarked on this later in 1927 in a speech at a meeting of the Central Committee:

It is said that in that “will” Comrade Lenin suggested to the congress that in view of Stalin’s “rudeness” it should consider the question of putting another comrade in Stalin’s place as General Secretary. That is quite true. Yes, comrades, I am rude to those who grossly and perfidiously wreck and split the Party. I have never concealed this and do not conceal it now. Perhaps some mildness is needed in the treatment of splitters, but I am a bad hand at that. At the very first meeting of the plenum of the Central Committee after the Thirteenth Congress I asked the plenum of the Central Committee to release me from my duties as General Secretary. The congress itself discussed this question. It was discussed by each delegation separately, and all the delegations unanimously, including Trotsky, Kamenev and Zinoviev, obliged Stalin to remain at his post. What could I do? Desert my post? That is not in my nature; I have never deserted any post, and I have no right to do so, for that would be desertion. As I have already said before, I am not a free agent, and when the Party imposes an obligation upon me, I must obey. A year later I again put in a request to the plenum to release me, but I was again obliged to remain at my post. What else could I do?

The next two attempts to resign from the post of General Secretary was a year after in 1926 and later in 1927. The British historian Robert Service who specialized in Russian history wrote about this in his biography of Stalin:

On 27 December 1926, he wrote to Sovnarkom Chairman Alexei Rykov saying: ‘I ask you to release me from the post of Central Committee General Secretary. I affirm that I can no longer work at this post, that I’m in no condition to work any longer at this post.’ He made a similar attempt at resignation on 19 December 1927.

All three of these previous attempts were rejected. The last attempt to resign was in 1952, about five months before Stalin’s death, during a meeting of the Central Committee where he urged the Central Committee to relieve him of his duties. This too was rejected.

In a speech given by him to the Central Committee that mainly criticized Molotov for some of his decisions, he was interrupted near the end of the speech by someone from the floor.