The 23-year-old striker joins the Reds after impressing in the SSE Airtricity League Premier Division with the Donegal side in 2021.
The Swords native had a particularly strong end to the 2021 season being nominated for SSE Airtricity League Player of the Month.
Prior to his season with Finn Harps, Sean played with Shamrock Rovers FC and Longford Town FC.
Sean also played for three seasons in the SSE Airtricity League Premier Division with Shamrock Rovers as a teenager.
Sean joined Finn Harps after he suffered an injury during a PFA Ireland trial match but has since regained full fitness with a number of goals at the end of 2021.
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Shamrock Rovers Finn Harps Longford Town