There are many great online courses to learn data structures, but here are a few of the best:

• Data Structures and Algorithms Specialization by University of California San Diego on Coursera: This specialization is a comprehensive introduction to data structures and algorithms, covering topics such as arrays, linked lists, trees, graphs, sorting, and searching. It is taught by world-renowned experts in the field, and it includes a variety of interactive exercises and coding challenges.
• Algorithms, Part I by Princeton University on Coursera: This course is a rigorous introduction to the theory of algorithms, covering topics such as sorting, searching, greedy algorithms, dynamic programming, and NP-completeness. It is taught by Professor Robert Sedgewick, one of the leading experts in the field.
• Algorithms: Stanford University by Stanford University on Coursera: This course is a more advanced introduction to algorithms, covering topics such as graph algorithms, computational geometry, and machine learning. It is taught by Professor Tim Roughgarden, a leading expert in the field.
• Data Structures and Algorithms in Python by University of Michigan on Coursera: This course teaches data structures and algorithms using the Python programming language. It covers topics such as arrays, linked lists, trees, graphs, sorting, and searching. It is taught by Professor Steven Skiena, a leading expert in the field.
• Data Structures and Algorithms: Deep Dive Using Java by Tim Buchalka on Udemy: This course teaches data structures and algorithms using the Java programming language. It covers topics such as arrays, linked lists, trees, graphs, sorting, and searching. It is taught by Tim Buchalka, a leading Java instructor.

These are just a few of the many great online courses available to learn data structures. The best course for you will depend on your individual learning style and goals. I recommend checking out the different courses and seeing which one you think would be the best fit for you.

Here are some additional factors to consider when choosing a data structures course:

• The level of difficulty: Some courses are more introductory, while others are more advanced. Choose a course that is appropriate for your level of experience.
• The programming language: Some courses are taught in a specific programming language, while others are language agnostic. If you have a preference for a particular language, choose a course that teaches that language.
• The instructor: The instructor is an important factor in the quality of a course. Choose a course that is taught by an experienced and knowledgeable instructor.
• The format: Some courses are self-paced, while others have live lectures. Choose a format that works best for your learning style.