Rubber composition and tire

A rubber composition having:

• at least three types of diene polymers forming a plurality of polymer phases which are immiscible with each other;
• and silica, wherein:
• each of the at least three types of diene polymers has content of ≥10% by mass with respect to the total mass of the diene polymers;
• content of the diene polymer (A) having the lowest glass transition temperature (Tg) among the diene polymers each having content of ≥10% by mass with respect to the total mass of the diene polymers is ≥85% by mass with respect to the content of the diene polymer having the highest content among the diene polymers other than the diene polymer (A);
• among the diene polymers each having content of ≥10% by mass with respect to the total mass of the diene polymers, the diene polymer (C) has the highest glass transition temperature (Tg) and a diene polymer (B), which is other than the diene polymer (A) and has glass transition temperature (Tg) lower than that of the diene polymer (C) having the highest glass transition temperature (Tg), has been modified by a compound containing silicon atom;
• the diene polymer (B) is a copolymer of a conjugated diene compound and styrene and satisfies formula (i) shown below:
• St+Vi/2≤33 (i)
• (In the formula, “St” represents content of bonded styrene (mass %) of the diene polymer (B) and “Vi” represents vinyl bond content (mass %) of the conjugated diene compound part of the diene polymer (B));
• and
• the silica has content of ≥25 parts by mass with respect to the total mass or 100 parts by mass of the diene polymers.