Cosmonaut Yuri is a minor human character appearing in the 2011 film Transformers: Dark of the Moon. He is introduced as a former Russian cosmonaut whose planned mission to the Moon was unexpectedly cancelled. This cancellation led him, alongside his fellow cosmonaut Dimitri, to live a more secluded and withdrawn life, eventually relocating to live in hiding within the United States.

Limited information is available regarding Yuri's individual personality, as his role in the narrative is brief and largely functions to provide exposition. He does not speak as much as his companion Dimitri, but instead plays a key role in revealing visual evidence of the mysterious discovery that ended their careers. When former Sector 7 agent Seymour Simmons and Sam Witwicky track the two ex-cosmonauts down at a dive bar, they seek answers about the true reason for the cancellation of their 1972 lunar mission. While Dimitri verbally explains that a reconnaissance mission named Luna 4 took photographs of the dark side of the Moon, Yuri physically presents the critical evidence. He shows the visitors a series of photographs depicting strange cylindrical rocks on the lunar surface, which also appear to show noticeable drag marks leading to them. This visual proof confirms that something artificial was present on the Moon long before the official Apollo landings.

Yuri's primary motivation within the story is not driven by active goals or heroism but rather by a desire to be left alone after the disappointment of his cancelled mission. His most significant relationship is with Dimitri, his partner from the cosmonaut program, with whom he has remained in seclusion for decades. They are shown to be inseparable in their retirement, sharing the same living space and maintaining their secret together. His role in the plot is strictly functional; he serves as the keeper of photographic evidence that pushes Sam Witwicky and Seymour Simmons further into the central conspiracy involving the Autobot ship the Ark and its missing pilot, Sentinel Prime. Regarding Yuri's development, the character is static; he appears in only one scene and does not undergo any personal change or appear again after providing the protagonists with the necessary clue. Similarly, there are no notable abilities or combat skills associated with this character, as he is portrayed simply as an elderly, retired cosmonaut living an ordinary life. No information is available regarding his motivations beyond seclusion, any specific aspects of his personality, or any character development arc.