As one of the six clubs to have won the cup Real Sociedad were invited to take part and were thus one of the founding members of the 1st division.
League matches were played from February to June 1929.
In the King Alfonso XIII's Cup Real Sociedad faced Patria Aragón, who they beat with ease.
In the next round Real Sociedad were knocked out by FC Barcelona, the holders.
Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.