A tread rubber composition, comprising: a rubber component; silica; and a silane coupling agent containing a mercapto group, the rubber component comprising a conjugated diene polymer in an amount of 5% by mass or more per 100% by mass of the rubber component, the conjugated diene polymer comprising a monomer unit derived from a conjugated diene, a monomer unit derived from a compound represented by the following formula, and a monomer unit derived from a compound represented by the following formula, at least one end of the copolymer being modified by a compound represented by the following formula or an alkoxysilane compound represented by the following formula, the tread rubber composition comprising the silica in an amount of 5 to 150 parts by mass relative to 100 parts by mass of the rubber component, V 1 -S 1 wherein V 1 represents a group represented by the following formula (1-V1); and S 1 represents a group represented by the following formula (1-S), wherein R 11 represents a hydrogen atom or a hydrocarbyl group; n represents 0 or 1; and R 12 represents a hydrocarbylene group, wherein X 1, X 2, and X 3 each independently represent a substituted amino group or an optionally substituted hydrocarbyl group, and at least one of X 1, X 2, and X 3 is a substituted amino group, V 2 -A 2 wherein V 2 represents a group represented by the following formula (2-V1); and A 2 represents a substituted amino group or a nitrogen-containing heterocyclic group, wherein R 21 represents a hydrogen atom or a hydrocarbyl group; m represents 0 or 1; and R 22 represents a hydrocarbylene group, wherein E represents an oxygen atom or a sulfur atom; and Z 1 and Z 2 each represent a substituted amino group, a hydrogen atom, an optionally substituted hydrocarbyl group, or an optionally substituted hydrocarbyloxy group, provided that at least one of Z 1 and Z 2 is a group containing a substituted amino group, or Z 1 and Z 2 are joined together to form, together with the carbonyl carbon atom, a cyclic structure containing a substituted amino group, wherein v represents an integer of 1 to 10; R 41, R 42, and R 43 each independently represent an alkyl group or an alkoxy group, and at least one of R 41, R 42, and R 43 is an alkoxy group; and A 4 represents a substituted amino group. a rubber component; silica; and a silane coupling agent containing a mercapto group, the rubber component comprising a conjugated diene polymer in an amount of 5% by mass or more per 100% by mass of the rubber component, the conjugated diene polymer comprising a monomer unit derived from a conjugated diene, a monomer unit derived from a compound represented by the following formula, and a monomer unit derived from a compound represented by the following formula, at least one end of the copolymer being modified by a compound represented by the following formula or an alkoxysilane compound represented by the following formula, the tread rubber composition comprising the silica in an amount of 5 to 150 parts by mass relative to 100 parts by mass of the rubber component, V 1 -S 1 wherein E represents an oxygen atom or a sulfur atom; and Z 1 and Z 2 each represent a substituted amino group, a hydrogen atom, an optionally substituted hydrocarbyl group, or an optionally substituted hydrocarbyloxy group, provided that at least one of Z 1 and Z 2 is a group containing a substituted amino group, or Z 1 and Z 2 are joined together to form, together with the carbonyl carbon atom, a cyclic structure containing a substituted amino group, wherein v represents an integer of 1 to 10; R 41, R 42, and R 43 each independently represent an alkyl group or an alkoxy group, and at least one of R 41, R 42, and R 43 is an alkoxy group; and A 4 represents a substituted amino group.