Does having ADHD mean someone can't be a good parent?

No, and there's no clinical basis for this assumption. ADHD affects attention regulation and executive function, which can create real, specific parenting challenges, staying on top of routines, managing frustration in the moment, but it doesn't determine warmth, love, or a parent's overall capability, which are the qualities that actually define good parenting. Many parents with ADHD manage these specific challenges well through treatment, external structure, and self-awareness, and research doesn't support a blanket link between an ADHD diagnosis and poor parenting outcomes. References: https://www.caddra.ca/wp-content/uploads/Canadian-ADHD-Practice-Guidelines-4.1-January-6-2021.pdf

Genuinely worried this was true about myself before getting real support in place. Structure, a good pediatrician, and eventually medication changed that a lot, my kids would tell you I'm a pretty involved parent now. Hearing my kids describe me as involved and present now still catches me off guard sometimes, given how convinced I used to be of the opposite.