[6] The first restaurant was opened in Ballinasloe, County Galway, in the West of Ireland in 1978, by Pat and Una McDonagh.

[7][8] As of November 2013[update], Supermac's was the largest Irish-owned quick service food chain,[9] with over 100 outlets across Ireland.

[2] The Restaurant was named together by locals and its owners: The founder, Pat McDonagh, earned the nickname 'Supermac' whilst playing Gaelic football for the Carmelite College in Moate.

As of 2018, the company's association with Galway hurling was the longest running inter-county GAA sponsorship in the country, then in its twenty eighth year.

[27] The company also engages with other sports sponsorships such as rugby,[28] soccer,[29] international rules football (2005) and horseracing (Limerick, Ballinrobe races).

[36] McDonald's won a partial victory, with the EU's Office for Harmonisation in the Internal Market (OHIM) ruling that Supermac's could trade under its own name in the EU, but it rejected Supermac's trademark applications for several items, including menu items.

In January 2019, the EUIPO ruled that certain trademarks owned by McDonald's, including Big Mac, were to be revoked.

[38][39][40] In 2023, the EUIPO Board of Appeals partially reversed the decision revoking McDonald's trademarks, permitting McDonald's to continue to use the trademark for poultry products and restaurants, but also permitting Supermac's to use the Big Mac name on its own food products.

On 5 June 2024, the court held that McDonald's had failed to prove use of the Big Mac trademark in relation to chicken products or in relation to services associated with operating restaurants, meaning Supermac's and other businesses are now free to use the "Mac" in their business names and in names for poultry products in Europe.