This chapter emphasizes the design of learner-centered assessments that both measure and enhance learning in online environments. It explores formative, summative, and alternative assessment strategies, highlighting ways to support diverse learners through authentic and flexible approaches. The chapter provides practical guidance on creating transparent rubrics, streamlining grading with LMS tools, and delivering timely, constructive feedback that motivates progress. It also addresses academic integrity, offering strategies and technologies to ensure fairness and uphold ethical standards in assessment design.