Green Days: Dinosaur and I (Korean: 소중한 날의 꿈; RR: Sojoonghan Nalui Ggoom; lit. "Dream of a Precious Day") is a 2011 South Korean animated film. Without the high-tech computer graphics and three-dimensional techniques that dominate the animation industry, the film was hand-drawn in pencil, with 14 animators using 100,000-plus sheets over a period of 11 years. It premiered at the 15th Busan International Film Festival in 2010 and competed for the top prize at the 2011 Annecy International Animated Film Festival.

Set in a 1970s rural town, Green Days: Dinosaur and I is a nostalgic coming-of-age story about a high school girl who struggles to find meaning in her existence and learns to confront her biggest fears, while also falling in love for the first time. Yi-rang (voiced by Park Shin-hye) has all but given up on her athletic aspirations, when she meets Cheol-soo (Song Chang-eui), who dreams of becoming an astronaut, and Soo-min (Oh Yeon-seo), a transfer student from Seoul. The film follows the adolescents' budding romance, growing pains, hopes and dreams.