Background: Understanding memory retention in children with developmental language disorder (DLD) compared with their typically developing (TD) peers enhances our knowledge of memory processes. Aims: To examine long-term memory consolidation of a declarative object-location task and a procedural symbol-writing task, along with grammatical and lexical skills, in 5-year-old children with DLD and their age-matched peers. Methods & Procedures: A total of 23 children with DLD and 30 TD peers participated. For procedural memory, children practiced writing a new symbol and were assessed 4 hours and 2 weeks post-practice. For declarative memory, they practiced locating cards until they achieved 75% correct responses and were assessed again 4 hours and 2 weeks post-practice. Results & Discussion: Children with DLD had fewer correct responses on the declarative-memory object location task with the gap widening significantly from 4 hours to 2 weeks post-training. On the procedural symbol-writing task, children with DLD showed overall lower accuracy. Furthermore, only their TD peers exhibited delayed gains 4 hours post-training in production times, while they narrowed the gap two weeks later. A speed-accuracy trade-off was observed during their symbol-writing practice. These results highlight atypical long-term declarative memory retention and procedural knowledge acquisition in DLD. Consistent with previous studies, declarative memory correlated with lexical scores in both groups, while procedural memory correlated with grammatical scores only in TD peers. Interestingly, long-term procedural learning was linked to lexical abilities in children with TD. Characterizing child performance in short and long intervals following practice may aid clinicians in supporting children with DLD beyond the clinical setting.