There are many great online courses available to learn data structures. Here are a few of the most popular and well-regarded options:

• Data Structures and Algorithms on Coursera by Princeton University. This course is taught by Robert Sedgewick and Kevin Wayne, two of the leading experts in data structures and algorithms. It covers a wide range of topics, from basic data structures to advanced algorithms.
• Algorithms, Part I on Coursera by Stanford University. This course is taught by Tim Roughgarden, a professor of computer science at Stanford University. It covers the fundamentals of algorithms, including sorting, searching, and graph algorithms.
• Data Structures and Algorithms in Python on Udemy by Jose Portilla. This course is taught by Jose Portilla, a popular instructor on Udemy. It covers the basics of data structures and algorithms in Python, with a focus on practical applications.
• Data Structures and Algorithms: Deep Dive Using Java on Udemy by Tim Buchalka. This course is taught by Tim Buchalka, a popular instructor on Udemy. It covers a wide range of data structures and algorithms in Java, with a focus on implementation.
• Data Structures and Algorithms Masterclass on Pluralsight by Gayle Laakmann McDowell. This course is taught by Gayle Laakmann McDowell, a former Google engineer and author of the book “Cracking the Coding Interview”. It covers a wide range of data structures and algorithms, with a focus on interview questions.

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 needs and preferences. Consider the topics you want to learn, the programming language you want to use, and the instructor’s teaching style.