Yes. Celery and Nasturtium have a documented companion-planting benefit. Virginia Cooperative Extension lists nasturtium as a companion for celery.
This is a practical yes, not a magic guarantee. Keep the normal spacing for Celery and Nasturtium, watch airflow and watering, and treat the companion note as one useful planning signal alongside sunlight, soil, and harvest timing.
Source basis: Virginia Cooperative Extension companion planting chart. The page does not add extra pest-control or yield claims beyond the sourced fact row.
Spacing tip: Use herbs and flowers as edge plantings so they help diversity without competing for the crop row.